more for example you find in 5 years time (as the rest of the world has already) that a 40mm AGL/7.62mm doesn’t cut it..... you don’t have to buy a whole new vehicle just a new module.How do you know we're not going to use the modularity? In five years, say you got your wish for a twin linked 57mm gattling cannon turret, and it became viable. Just pop off the current body, and stick in the new one. All we'd need to do is buy new bodies.
It literally allows through life upgrades and replacements. Making the "Upgrade it later, when we have more cash" approach more likely. Or we UOR something, in it goes.
Hell, It'd likely be worth buying a few extra chassis now while they're cheap, just while the costs are low.
Errrr era 1970's chassis...? Why don't we just stretch the wheelbase on a Saracen then? Its about the same technology level.
There is even an existing design for a 30mm armed IFV that can carry 3 crew plus 6 infantry