I don't like mixing cone types - not even different models of just 10s or just 12s etc.
I always find that the perfect EQ for one cab / speaker is not the same as for the other so there's always a compromise that cannot be dialled out - at least not without cross overs or a completely different amp feeding each cab.
If it was me, I'd pick the cab I liked best and just get another of the same. No compromises then and also no option paralysis in choosing which one to take on a smaller gig when only 1 is needed.
It's not going to sound awful by any stretch of the imagination, but it might not sound exactly as you want. If you are relaxed about that - then no problem.
Give it a try and see what happens - nothing will go wrong and your band mates won't even notice as long as they aren't asked to help you carry!