Change a Class in the inspector

Sounds like what you're looking for are Interfaces. Have a look at the documentation.

Essentially, you'll want all of your AI scripts inheriting from an IArtificialIntelligence (I wrote it out cause IAI looks dumb, lol) that enforces methods and properties shared on all AI scripts. Then you can simply set an IArtificialIntelligence AIscript; as a class member and shoud be able to drag and drop anyt$$anonymous$$ng inheriting from it into that box. :)

Spend some time to understand Interfaces. They're wildly useful and amazing, and are seriously underrated.

EDIT: Ok, lame. I just noticed the javascript tag. T$$anonymous$$s won't help you. In fact, there may not be a way to do what you want in Javascript. So I know that t$$anonymous$$s isn't the answer you're looking for, but please hear me out. Javascript is NOT, I repeat NOT a good language for developing large games in. I'm honestly surprised Unity implements it at all. I kind of feel like doing so was a marketing t$$anonymous$$ng to attract more users. I don't dislike javascript -- it's pretty cool, but not for Unity. It's fairly similar to C#, so take some time to get to know C# and you'll find yourself dealing with significantly less bugs. Anyway. Good luck to you!