In one very long 4v4 game I had something like 6000% efficency on Rear Echelons. NURF REs!
On a serious note:
if you struggle with T-70 on a regular basis, a replay in state office section for strategists to analyze would be more helpful for you, unless your goal is just to spend some time theorycrafting for fun without real scenario.
I have no problem fighting against it, what I am stating is that I can easily get 600/800% efficiency with a T70 when using it myself. I love the thing, but it rapes way too good.