As someone that plays Evols all the time, I can tell you that there are really only ~7 good Evoltile and Evolsaur monsters, of course, if this is for IRL I do know that the good ones kind of cost money. Good monsters and why:
Evoltiles:
Westlo - The bread and butter, should be at 3.
Najasho - Hilariously powerful with Evo-Force, good with Enemy Controller (which should be in, especially if you have Casino) This can go to three, especially if you want to run trib
Casinerio - A quick one-for-two if you can kill something, shouldn't be run past one, can be left out.
Odonto - A very iffy card. Best used should you draw Vulcano. I like having one for such occasions.
Evolsaurs
Cerato - 2100 when special summoned AND searches when it kills something. Has 1900 to crash with pesky Thunder Kings. Definitely goes at three.
Diplo - S/T destruction with backrow crazy decks running around is good. 1600 attack, is not. I like to keep it at 2.
Vulcano - An amazing effect that nets you a rank four when successful, however, at 1200 it is often a bad idea to run more than 2. 1 is okay, but having 2 gives you its ability twice.
I only suggest against the 5+ guys because they're even slower than Evols already are, and it gives you more room for the great Rank 4s that exist. I can tell you now that Force should be at 3 (it's so good, why wouldn't it be at 3?) I'd suggest at least trying out E-con (especially if you plan on using Casino) but I can tell you it's pretty great. Forbidden lance is also nice as it'll protect Evolzars from harmful spells/traps AND make big monsters weaker.