Again, I'm unfamiliar with Southern Mantis, so this doesn't help.The strategies are fundamentally contradictory and the tactics of each are designed specifically to function in those terms. Flip the script and they no longer function.
Ah, I think this is what you're referring to:This thread!
The empty hand uses an upright and squared body structure, emphasizes "short bridge" and pressing attacks. But the way VT empty hand functions is very unique, in that it is based on tactical guidelines from the pole and knives.
The primary and auxiliary hand actions map to the primary and auxiliary pole actions, i.e. fong-lung-cheung (pole thrust) and the punch are the main actions, leung-yi and kam-gwan are auxiliary actions for the pole to open the line for the thrust, just as paak-sau and jat-sau do for the punch. All other actions are for returning to the primary.
Tactically, the guidelines are using short shocking power for displacement and aggressively capturing space for the strike. The shaft displaces while the tip remains aimed and blasts in with the strike. There is no stick and follow.
In empty hand, we face squarely to enable simultaneous use of "two poles", using the forearms (shaft) to displace while maintaining aim and striking with fist (tip). This ability is developed in daan-chi-sau, where two "poles" are in a face-off to develop the other's ability. Initially two beats for training become one in fighting.
Without knowing the tactical guidelines from the pole, and that they are the basis of the empty hand method, many get trapped in a game of "stick, follow, roll" instead of displace and hit directly. In fighting, the former doesn't work, the latter does.
I didn't process those fully at the time, apparently. Those are significant alignments between pole and empty-hand (I'm assuming your assessment here is accurate - you'd know better than I). The issue is that this would also be the case if an empty-hand method existed, and was adjusted to be more effective. Again, it's not contradictory to your conclusion, but not contradictory to at least one of the other possibilities that have been presented.
I've never really thought of it as a "proto-style". I've been considering the possibility that the physical principles were sourced from an existing art (perhaps one of those noted with superficial similarities, perhaps not). I suppose the possibility of a hybridization of empty-hand work is possible, which would yield a proto-style. Either way, if it originated as either a derived style or hybridization into a new style, including mostly or only empty-hand, and someone along the way started incorporating some principles to improve it (to, perhaps, avoid the stick, follow, and roll), they'd pull principles from somewhere. Perhaps they had some spear experience or knew someone who did, and used those principles to improve the style. Then they want a pole form (not wanting spear, because it's harder to come by or more dangerous to train with, or whatever), and start looking at other arts. They find this pole form that appears derived from spear. They see it as a good fit, borrow it with little or no adjustment, and then fit the training methods around it so it fits seamlessly into the art.Then it's pointless to talk about a "proto-style". It's indistinguishable from a fully new constructed one.
Or, they found the form first, thought it would be a good basis for empty-hand work, and borrowed bits and pieces from elsewhere (thus the similarities) and fit them around the tactics of the pole.
The evidence seems to work equally for both sides. There's no strong evidence that WC existed without the weapons (that anyone has presented here), and also none that it existed without the empty-hand. We know other arts have done both, so neither is all that unlikely.