Do you think you could do it with two horses? Losing that second stall and doubling the gear (let’s assume nothing shared between horses, but rider gear stays the same)?
I’m pretty sure I could make it work with the camper shell + tack locker for one horse. But I can already do that with my current rig - the idea is the Euro trailer for hauling two (since doing longer distances that way with this setup is pushing it on capacity more than I’d like).