We ride in very loose sand, lumpy as buggery, no huge hills, no real rocks to speak of but plenty of trees and stuff to run into/over, then often out onto the local limestone marble gravel on hard packed unsealed road. It's not the most challenging terrain I grant you but it still hangs up quite a few guys on pretty good bikes and yet I make it through on a pile of junk. We have Enduro races and other pro events on the same land though I've not competed myself, ( I simply have no inclination to, nor do I get a buzz from competition with anyone but myself). My rat bike isn't a Versys by any means and I guess by saying so I'm diverting from the original topic about it being the bike in question.
If we bust a bikes purpose down to the core level, it's about transport. It's about carrying your arse from one place to another with the most safety and efficiency. If a bike gets you from A to B without removing skin and within a reasonable time frame, I'd say its 'capable', regardless of the terrain crossed.
My pile-of-crud gets places it was never designed to go just by adding some crusty offroad tyres and riding it with some knowledge. It just didn't work in the sand, or on the loose crud on the road with the original skinny pavement tyres, all it did was spin on the spot in sand and do its best to dump my ass on the gravel. Adding those knobblies transformed the bike. It's the same story with cars. Ask any racer about whats the first thing to change when you go from street to track and you'll find 99 times out of 100 its wheels and tyres.
In short, add knobblies to a Versys and I think you'll find it goes all sorts of places you couldn't go before you made the change. By the looks of it, your substantial stable would give you ample opportunity to test this. Jam some road tyres on one of your dirt bikes and see how quickly you come off...
There's a reason why we have drag slicks, why we have water dispersion grooves and gator skin knobbles.
Oh and to rub a little salt into the wound, my Uncles very well maintained and kept Honda XR500S (late 80's, last of the drum brakers), is an unforgiving twitchy pain in the ass in the same terrain. I'm happier on my pile-o-poop, forgoing the power for some more controlability. His Honda has dumped me many more times than the junkpile, mostly because I don't modulate the grunt well enough. I'd be willing to bet that you would much prefer the Honda to the POS and you'd probably get around the track far faster than I ever could... and viola.. we come to my last point, personal style and preference.
As a sidenote : Experience is a double edged sword my friend. It gives you many advantages but it also dulls your ability and capacity to accept different ways of doing things. Hard won modes of operation, hard won skills are precious, no doubt about it but you always need to leave room for the possibility that you can do something another way.