From my experience,I would say DON'T overstock your tank. I have a heavily overstocked 75g African tank. And I can only speak for myself but it's not really cutting down on anything. 50% water changes weekly with sometimes 20% maintenance changes during the week. Over filtration, fx5 and a AC110 running on the tank. I've lost some good fish and still have some good ones left. Sometimes I'll get a dead fish everyday for a week!
And what's that mean? More water changes! So I get the overstocking to reduce aggression but how about this idea. Stock the tank with the proper species of fish that can coincide with one an other instead?
I went the other way and it's been a battle at times. You live and learn. You of course do what you want, I'm just speaking from what I've been through. It's not worth it IMHO in the long run.
Here's my overstocked tank. Do I love it? Yes o course! Would I do it again? Nope, I would do more research and stock properly and do the male to female ratio as well.
Again this is just me. But there will be unneeded deaths of some the right way and you and your fish will be happier then just throwing a bunch o Africans in a tank to hopefully cut back on aggression (which I did) when I stocked correctly you may not have any issues and just be able to relax and enjoy your tank rather then netting dead fish every few days and re homing a couple here and there.
I admit my faults but at the same time love my tank. At the moment there are some major battles going on and 4 females holding which makes it 100 times worse. There thinning the tank out themselves as they see fit.