I am not 100% certain on what to recommend, assuming it just need to be a Action x School theme involved in it. Also, the animes I am recommending aren't the types that I would want to rewatch, some are pretty meh, others are alright, some good. But if you are after the Action x School theme then these hit the mark, somewhat.

The Asterisk War
The Asterisk War 2
Not a big fan, but it's good, it also in all honestly has good action in it, with a distinct school vibe.

Sky Wizards Academy
One of the more worse animes I've watched but hey, it got that action x school theme. So check it out yourself, it follows that lane pretty well.

Wise Mans Grandchild
Well... This is one of those where I absolutely loved the everything except the ending, follows the school path well, action is well... In the more lacking, but it's there! Just not as much.

Blue Exorcist
Blue Exorcist Kyoto Saga
Ye... I don't love it, it's alright. Has action, in a school environment though, it's alright.