Might be unpopular with this, but here goes: it really depends on what you are trying to achieve for him;
If he's successful in school / college/ University and is accepted for Air Force, they will train him "from Zero to Hero" ; any amount of time he has spent on msfs won't count for anything as " its not real" . The only thing it could be useful for is gaining an appreciation for ADF/ILS/ DME arc navigation procedures, and for that the basic C172 in sim is good enough.
Tying it to any possible type he might encounter during training depends on the fidelity of the particular model and an awful lot of real world operations and considerations are not written into msfs, or fudged, because MS didn't program it properly ; weights and performance, management of bleed air and cabin environment for example, the correct method for starting (I know some folks practice cold and dark but again " steps are shortened and sequences changed")
Ttfn
Pete