So what is the reason for going T-1 now?
Because Penals are superior to Conscripts, especially scaling wise (on an individual basis, but Con spam is very strong), Sniper is incredibly good on open maps and M3 is a nice sniper counter as well as an excellent way of aggressively clearly MG's from garrisons with Flamers. Overall, it's a more aggressive playstyle than Tier 2 which relies on Support weapons. Without any anti-tank, Tier 1 would be prevented from realising that aggressive potential.
We are also working on some more anti infantry utility for Penals in v1.3 to make them more desirable and flexible without making them necessarily stronger.
Realistically, T1 isn't so attractive at the moment because of how OP maxims are currently, but Maxims will definitely be getting nerfed next patch (if we get that far) which will make Tier1 a bit more attractive.