This is way too situational. There is also no way that you will ever be able to gain veterancy when playing vs USF (I know this is an EFA-only mod; but I don't think we will be adding stuff that's not there, when we go to other factions).
Thing is, if they don't plant mines you don't need to buy a sweeper. pios without sweepers are decent enough in a fight to get to vet 2 normally, and especially with flamethrower. I thought the point of the change was to help sweeper engis?
If not that, I really don't see the point in making the change. Without sweepers they vet up fast enough where this is unnecessary, and with sweepers clearing mines is much more simple and less exploitable.