Pros and Cons of a tent on the ground and its alternatives in Namibia

I am leaving for a three week vacation in Namibia in May (past rain season). A 4x4 car is rented and I plan to bring my own tent (and most other required camping gear). I've been on camping trips all my life, like to sleep in a tent, even on hard ground, and even just in sleeping bags without tent.

The alternatives that come to my mind are

• Tent on the ground
• Rooftop tent on the car
• Sleeping bag on the ground (no tent)
• Sleeping bag in back of car

Currently my favourite is a tent on the ground doing without the outer rain protection and just using the inner, meshed fabric, similar to this one Advantages are:

• Easy to put together, quick to tear down
• Mosquito protection
• View to the stars

Neutral is:

• Little temperature isolation

Disadvantages include:

• Less protection against some animals (Hyenas)
• No rain protection

How feasible is this option?

Is any fear of Hyenas exaggerated? In my experience small aggressive animals such as squirrels and other little critters can make life more miserable than bears, but I haven't been exposed to African wildlife yet. Should I be concerned about baboons?

I'm fine with fleeing into the car if rain starts or just pull over the original rain protective outer shell of the tent.

What do you think about the alternative of a sleeping bag in the (partially open) back of the car (4x4 single cab, e.g. Toyota Hilux)?