Locked gauntlets: quite rare
higherBAB/STR/bigger weapons: I guess vs +26 it's a bit hard even for a full BAB class to get a higher mod without the improved disarm feat. There are no bigger weapons tha na two-handed one (and Robin Hood can also get enlarge; but watch out for the DEX penalty -wait until lvl 11 for that...)
And monsters? Well, as I said, the full usual rogue tactics are available against those on top.
But true, two Robin Hoods stealing from each other would be hilarious - the one going first likely wins, as he lifts the masterwork item off the other one first...
- Giacomo