That's a nice photo, I like the looks of the bow on the far right. Redman? What wood combo is that?
When it comes to Hills it seems everyone has their own way to hold them...and they'll all swear it's absolutely the best way, lol. I suppose they're right if it works for them.
Like your bows, my Hills feel quite different in the hand (three are straight-grip, the fourth is slightly dished). The only constants I've found for Hill designs is the need for some bend in the bow arm, and to use a FIRM grip...firm as in maintaining good/solid palm contact and control of the bow but not choking the stuffing out of it and not letting the bow simply sit lightly/barely in the hand. Light-mass bows generally don't do well with a very light (recurve style) grip on the riser. I've found that effective grip tension on a Hill is not unlike how one would approach holding a firearm. Most wouldn't hold a physically light but moderate-to-high recoil caliber rifle or pistol with a soft touch and expect to hit much. Firm 'snug in' control allows the shooter to maintain proper alignment through the shot. Heavy-mass, low recoil target guns are quite different than lightweight, moderate recoil sporting guns when it comes to how they want to be handled. And so it is with bows.
A comfortable "handshake" approach fits the bill nicely for hand contact on Hills, especially when faced with shooting from odd angles or in difficult conditions. For getting comfy and consistent, 'getting ahold of it' as Hill said makes alot of sense.
But back to your bows. How do you like that deep-core, slightly dished bow on the far left? Looks a little like the grip on my Ruffed Grouse...feels good in the hand I'll bet.