Yes, it would be a bad idea.
Blue acara,
Aequidens pulcher, like most acara are best kept fairly cool. They'll live longer and exhibit nicer colours if kept properly. You're aiming for about 22-24 degrees C as the optimal, though a little cooler, down to 18 C in winter, is fine.
Standard rams,
Mikrogeophagus ramirezi, need to be kept very warm, 28-30 C. There's no overlap between this species and the blue acara, so however you kept them, one would be stressed, if not both.
The Bolivian ram on the other hand is found in cooler environments and will be happy at 22-26 C. As such, you could set the temperature of the tank to around 23-24 C, and keep both Bolivian rams and blue acara perfectly well.
Do note that
Corydoras mostly despise being kept too warm. With the exception of
C. sterbai, none will be happy at 28 C and most should be kept at or below 25 C. There are reports of
Mikrogeophagus ramirezi biting the eyes out of
Corydoras, e.g., in Loiselle, so it's not a combination I would recommend.
Cheers, Neale
Would it be a bad idea to put 1 or 2 blue acaras in a large tank with rams and corys?
Heavy planted with a ton of bog and mopani wood