If you made T2 cheaper, you'd shunt the removed fuel cost to Battle Phase 1 to maintain the timings. Removed manpower could go to BP1 or BP2.
I think locking shrecks to T2 is a cleaner solution though.
Imo this is a problem of all faction and should be addressed for all factions.
The timing of infatry should follow mainline infatry and all units available early should follow the PF approach (although the implementation of PF seem make them UP ). They Spawn weaker (at similar power level as the mainline infatry) but have weapon upgrades via tech available to them.
PGs for instance could span as a 260-280 with M40 or some other weapon combo and be able to buy weapon upgrades.