Small God of the Dozens
I think that for a lot of campaigns it makes sense to go with the mostly hand-waving approach that's in the core rules. No real conditions and modifiers, with animal handling to cover fancy riding. If the campaign was going to be one where the party is often outdoors and for whatever reason will feature a lot of mounted combat, then I'd start thinking about some homebrew to flesh out the details. Same goes for ships really, I don't need complicated ship rules unless I'm running a nautical campaign.