Wouldn't Rangers be more expensive in that scenario?
Even with the 50 less MP upfront, they would still be more expensive, outside of reinforcement cost. Unless you count 3 vs 4 in 1 man retreat circumstances where they would be more expensive too!
Rangers in larger modes means giving up the Priest, maybe Urban Defense can finally dispute Infantry throne in such modes, but I highly doubt it considering how many want to replace the Calliope with some other tank and make this Commander irrelevant in larger game modes.
340MP (obers) vs 350MP (rangers), and 80 muni LMG vs 90 thompson, to win every CQC engagement and compete in open field charges. I would most definatley pay that little discrepancy for those results.