Has anyone seen the Tekton "The perfect Set"? It has a few tweeters in each cabinet!
But if you read the white paper on the design behind this, it is not just sticking a few tweeters in the cabinet.
They are all acting as one driver. In other words, lobing, phase, cancellation, etc, are all taken into consideration by Eric Alexander in the placement and crossover design.
He has several very informative vids on YT explaining the reason for the design. And again, it is not just sticking a bunch of tweeters in a cabinet.
I will reiterate what I said months ago, the chances of getting a good, flat frequency response, with phase not becoming any worse than one pair of the speakers being used, with no weird new, cancelations, standing waves, increased dips or bumps in the frequency response, or other unpredictable results, are not good.
If one likes the result, that is fine. Maybe you like whatever frequency aberrations are caused by multiple drivers operating at the same frequencies.