Dyer Promises said:

I have an idea for training more troops at a time. If it was possible to train troops in seperate barracks. Meaning having multiple training sessions going at once. It would help build stronger armies and bigger wars for all.

Hello :)

If you want to train more Units, you can use boosters. 

Devs won't add one more building for it. First of all, it will require a lot of time of different teams (designers, developers, game designers) and they already have a big backlog of the new features.

Secondly, it will lead to changes in balance.