Risk vs Reward

I think he meant more specialised in the sense of more advanced.

Because more specialised == more roles

It is. But if you were to be building t2 units instead of the t1 units, you would be getting more bang for your buck.

You can afford to build more t1 factories per t2 factory. But you can only afford to run 3 t1 factories per 1 T2 factory.

That's the complaint. As a short term solution, t1 is viable. But in the long term, you should try and get as far away from a T1 army as you can.

I'm really relieved they haven't made t2 anti-air. Once that happens, advanced and basic are dead, it's the T1 age and the T2 age. Thankfully skitters, booms and AA dont have better versions of themselves at T2.

They could get around this by having different kinds of AA. For example they could have a T2 AA that is very good against gunships but horrible against bombers.

Edit - sorry. I was thinking specifically of flak vs missiles. I.e. anti-air that was just bigger and better.