But you can't make something extremely cheaper then other techs. It's fair to let your opponents to get some counters against it. It doesn't have to completely obliterate it, but like I told you multiple times. By the time the first stuff rolls out it's 7 minutes. (Early game is not about light verhicles but about infantry gameplay)
OKW have pumas and stealth puppchens.
Ost have 222s and PaKs.
Additionally you can use Ost doctrinal pumas.
Also before someone rushes in with "but it delays medium armor", well, T3 light vehicles doesn't exactly speed up the T4 either, getting more then single one means you'll be fighting med tanks with SU-76 at best. There comes also munition management(sorry, you can't spam LMGs to your hearts content with impunity anymore).
All of these keep light armor at bay.
Counters arrive before the light armor.
The "problem" is, many people thing ost T3=sov T3 and think "counters" to light armor should be medium armor arriving at the same time. Do I need to remind that it was the exact reason why light armor play completely extinct?
Sure, T-70 or quad will obliterate you and force you off the field, but only if you won't anticipate it and prepare for it at all.
Now, check old replays and see what allies did against fast luchs, then do the same against T70 and stuarts.