UK Standard Visitor Visa refused...what can I change when reapplying?

This is my father's refusal letter, I am the one who filled his application and wanted to ask about some points so I would rectify the mentioned mistakes when replying. My brother got a nearly similar refusal since he too is self employed and owns his own company. Kindly find below both refusals.

1-Fathers refusal

The decision
I have refused your application for a visit visa because I am not satisfied that you meet the requirements of paragraph(s) V4.2 ~ V4.10 of Appendix V because

You have applied for entry clearance to the UK for a period of 15 days accompanied by your spouse, son and daughter in law.

You state that you are self-employed as a manager and partner and earn ******* per year. In support of this you have submitted a copy of a commercial registration document bearing your name for ******* Company. However this document alone does not satisfy me that your salary is as claimed.

You state that you intend to spend £2500 on your proposed trip and have submitted copies of bank statements in the name of your company however none of the documents provided indicate that you have access to these funds for your own personal use. Furthermore | note that there are several recent large cash deposits into account ending **** that are not commensurate with the previous transactions.

«Given the above | am not satisfied that you are a genuine visitor and that you will leave the UK at the end of your visit, | am not satisfied that you are genuinely seeking entry for a purpose that is permitted by the visitor routes (these are listed in Appendices 3, 4 and 5). | am also not satisfied that you have sufficient funds to cover all reasonable costs in relation to your visit without working or accessing public funds. This includes the cost of the return or onward journey, any costs relating to. dependents, and the cost of planned activities. Your application is refused under paragraph V4.2 (a), (c) and (e) of the Immigration Rules.

2-Brother's refusal

The decision
I have refused your application for a visit visa because I am not satisfied that you meet the requirements of paragraph(s) V4.2 -V4.10 of Appendix V because:
You have applied for entry clearance to the UK for a period of 29 days to accompany your spouse and parents to the UK.

« You state that you are self-employed as CEO of **** and earn ***** per year. In support of this you have submitted a copy of a commercial registration document bearing your name for *****. This document alone does not satisfy me that your income is as claimed and the error in the spelling of your own company name undermines the credibility of your overall application and intentions for visiting the UK at this time.

• You state that your father will provide £5000 towards the cost of your proposed trip however you have chosen not to provide any documentation from him to indicate that he has agreed to this arrangement. | also note that you have only supplied copies of bank accounts in respect of your company and nothing in your own name to confirm that your income is as claimed.

I am not satisfied that you have accurately presented your circumstances and therefore your intentions in applying to enter the United Kingdom or that you have sufficient funds to cover all reasonable costs in relation to your visit without working or accessing public funds. This undermines the credibility of your application to the extent that I am not satisfied that you are genuinely seeking entry as a visitor or intend to leave the UK at the end of your visit. Your application is refused under Paragraph V 4.2 (a) (c) and (e) of the Immigration Rules.

1)You state that you are self-employed as a manager and partner and earn ******* per year. In support of this you have submitted a copy of a commercial registration document bearing your name for ******* Company. However this document alone does not satisfy me that your salary is as claimed.

2) You state that you are self-employed as CEO of **** and earn ***** per year. In support of this you have submitted a copy of a commercial registration document bearing your name for **** This document alone does not satisfy me that your income is as claimed and the error in the spelling of your own company name undermines the credibility of your overall application and intentions for visiting the UK at this time.

It seems in both refusals they assume the commercial registration documents were submitted as proofs of income while they were solely meant to be proofs of ownership. I thought the source of income should be inferred from the submitted bank statements. The error in my brother's company name spelling is a minor error due to translation from Arabic.

My question here is how can I show it was not meant as a proof of income and to consider the bank statements instead ?

1) You state that you intend to spend £2500 on your proposed trip and have submitted copies of bank statements in the name of your company however none of the documents provided indicate that you have access to these funds for your own personal use. Furthermore I note that there are several recent large cash deposits into account ending **** that are not commensurate with the previous transactions.

2) You state that your father will provide £5000 towards the cost of your proposed trip however you have chosen not to provide any documentation from him to indicate that he has agreed to this arrangement. I also note that you have only supplied copies of bank accounts in respect of your company and nothing in your own name to confirm that your income is as claimed.

I have no idea what type of document they refer to when saying "however none of the documents provided indicate that you have access to these funds for your own personal use". He is the company owner and literally the only person who has such access. If there is such document that will render these accounts sufficient, please let me know.

The bank account mentioned for having recent large cash deposits is an account in the local currency that had much less amounts than the USD account and the "large cash deposits that are not commensurate with the previous transactions" are not at all large compared to the other account provided which they chose to ignore. I will not be including this account when reapplying since it was not needed in the first place.

Moreover regarding my brothers claim to his father's sponsorship. They applied as a family (as recognized in both refusals headers) and both applications mention so, also my fathers application clearly mentions in the footnote that he estimates £2500 for his own expenses but he will be paying for all the family trip expenses. Yet they ask for "documentation from him to indicate that he has agreed to this arrangement". This part I can solve by getting such a letter from my father even-though it seems redundant.

I believe the main reason for the refusals is that both of them are using their business accounts as proof since their personal accounts are not in use and not indicative of their incomes. Unfortunately it is not possible at the moment to start documenting income through their private accounts, therefore, I thought of providing a cover letter explaining the issue and stating that they are the sole owners of their companies and only they can access their company accounts, yet, I am open for any suggestions.

I can not understand how the ECO thinks they are not genuine visitors who will leave after their visit. The supporting documents had many assets in their names and they have family (me and my younger brother) left at their home country. I am clearly lost in this application process and in desperate need for directions. If any one can help, it would be highly appreciated.

To sum up my long description, here is what I intend on changing when reapplying:

1- a letter from my father stating he approves of the sponsorship agreement for my brother.

2- a cover letter explaining why company accounts are used instead of personal accounts

3- exclude the problematic bank account which is not needed to cover the trip costs

4- change the trip duration to be only 2 weeks for both of them instead of my brother traveling earlier