The bullshit is strong. Short of a fluke where you managed to start with a 100 psi strength soldier who also had amazing stats you would lose every single mission against mind control. Since you can't see psi strength until you capture a psi enabled alien...
I'm sorry that you've failed to do that, if you wished. The mechanics of the original game are straightforward, and there's no overt shenanigans like in TFTD. Be patient in the combats, don't bring any weapons that you will kill yourself with when you get terrified, and be prepared to lose a lot of fights and start again with a fresh soldier. It's doable. My limit wasn't imposed on number of interceptors, or on tanks for base defense. Just for offense missions. You can't afford to make a single mistake, but you can win it. Well, maybe; I did.