isn't rps a repersentaion on cost and build time?

Most build times is repersentaion of units strength?

Economy controlls how fast you can build a unit at a time, which can decrease its build time if manufactory is allowed and can produce.

each base can only hold enough supply pads and a factory for 1 unit at a time.  so multiple production units require multiple bases. 

So in this game low rps doesnt hurt since, all units are limited to one base anyways so the nerf of adding small delay does nothing since low rps allowes it to get around the build time.  If they raise the rps by the cost it keep the warthogs the same speed to other units so its no more then anyother unit.   That is whole point of increase of build time anyways is to stop the exsevie spamming.