For a stock barge? I don't think the real answer is one or the other (clearance/traction). There's more to it than that. (This is going to be like a trip report from here).
The trail starts with a moderately steep climb of about 40-50m under a heavy jungle canopy. Meaning that it's permanently shaded, damp thick rainforest leaf litter on a reasonably firm clay base. Moss covered rocks of varying diameters (from bowling ball size to Volkswagen Beetle size) protrude above the soil to varying degrees from just a few inches to several feet. Rocks spaced such that almost everywhere at least one wheel will always be on a rock.
Right at the outset traction with AT tyres is an issue. My defender idled up but not without some slippy slippy shakes and hops. A stock triton went up before me but he had to charge 3-4 attempts. The modified, lifted, large tyred Jeep Cherokee before him cleared easily.
At this point there is a tight right turn putting your vehicle side-sloped (the trail isn't a graded level path) and an immediate drop, while side sloped, into a V-gully. The banks of the gully are about the same length as my 110" wheelbase. There is an 18" wide stream flowing at the bottom of the V over rounded rocks and holes. The included angle of the V was such that I just dragged my stock towbar at the rear.
As soon as front wheels start up the far side of the gully you need hard left lock. Still side-sloped here, turning head now more towards uphill to exit the V-gully at an angle between a large tree and a large boulder. So all kinds of cross axle action happening, at weird side angles, as you enter and exit the V-gully, all on the side of a slope.
My defender walked through this. This was the part that really surprised me regards the stock defender capability. This is where some of the others in more modified vehicles had issues.
I suspect that stock suspension on the defender was better at keeping wheels on the ground through odd angles than (some) of the jacked up barges. Also thinking that having the centre diff unlocked when side-sloped and turning tightly across those odd angles helped.
I wasn't really paying a lot of attention but did notice one of the modded barges had a rear wheel lifted where I did not lift a wheel...when rear diff was locked the rear wheel still on the ground just broke traction. (Downhill side on side slope with vehicle wedged against a tree). I had steered around the bigger trees and rocks without slipping off my line (much).
Up a little further the Cherokee kept going and my lack of clearance stopped me following.
So clearance ultimately stopped me. Lack of traction(?less driving wheels on the ground) stopped a truck or two with plenty of clearance for that part of the trail.
Slippery side slopes are one place where I have found that having less than 4 wheels differentiating means you slide down slope a little (or a lot) for every bit of forward progress across the slope. Unlocked diffs (incl center diff) may mean a little downhill slippage traversing side slopes. Locked centre diff (and part time 4wd in 4wd) means a bit more side slip traversing. Locked front/centre/rear diffs means a LOT of side slip while traversing (have seen 1:1 in some conditions in the jungle!)

