Overstocked bottom?

Right now I have 1 albino cory and 3 black Kuhli loaches in a 29gal. I would like to get another couple cories and maybe another Kuhli or 2, is this going to be to many on the bottom or does it matter as long as they have enough to eat and the tank isn't overstocked?

Before I get anything else I am going to finish tearing down the 10 gal then restart it. The guppies are going in there for sure and I haven't decided about the mollies, but both of their numbers are going to get pared down to the few I like best for breeding to trade into my lfs for other fish or equipment. Depending how the breeding goes this might be the best way to squeeze in another tank, the actual problem is were to put it!