The whole point of the commander? There shouldn't be a linear way any commander forces you to play. If a player wants to make the current fragile UC a command vehicle they should be able to. It's simple risk/reward.
A UC as a command vehicle was OP in the past because A) the recon was free and a no-brainer, and B) it applied the aura to emplacements where it was safe from counter-play. Both have been nerfed, and rightly so. Your preference on how a commander "should" be used isn't a good enough reason to limit player options.
If we lived in a perfect world, it would be pretty cool if you used command vehicle on three different tanks you get three different auras.
Centuar: Buffs infantry
Cromwell: Buffs tank speed/firespeed
Firefly: Buffs anti-tank capabilities