If Cooper is facing a lot of left-handers, then so is Carter. Nothing wrong there.
Your bullpen is thin. Sometimes you get away with that. Sometimes not. If five of those bullpen losses are switched to saves, you are reasonably happy right now. Otherwise, it looks like a solid team. You are more than 50 runs to the good so far.
Mostly, I think your problem is the division. You have OT and Arkinals to get by. The other stiff is running an experimental team that happens to be working so far.
I just had a team finish fourth with an 84-78 record. You get in those divisions sometimes.
If you are dying to do something, maybe you trade for a bullpen upgrade. Or you could slip HAL a $20 bill to get better dice rolls.
Good luck the rest of the way.