I'd recommend, at max, having 8 Machamps at Level 35+ and 4 Hariyama's at 35+, all with Counter/Dynamic Punch. That's two full Raid Squads - which should be more than enough for any raid you'll ever do with them. Hell, you might only need 6 Machamps and 2 Hariyama - one Raid Group, mixed up when appropriate - if you have an abundance of Max Revives and have a fast enough phone to use them in the middle of a Raid.
Don't discount Hariyama - it's not as attack-heavy but it takes a lot more damage. It's usually good to have at least 1 Hariyama on a Fighting Squad, particularly if you don't dodge. (for whatever reason; I don't dodge because my phone lags on a regular basis, so half the time it looks like I dodged but I actually didn't. I'd rather get an extra Quick Move off than try a flip-a-coin-dodge.) You don't want a squad of Hariyama, but adding 1 or 2 to the squad is almost always a benefit to you.