The difference is in the vertical pattern in the crossover range.
Horn loaded response will add a little gain in the below the crossover range, but require more EQ to even the peaks and dips out.
For small gigs, getting the horn above head level gives the advantage to TMM.
Haven't checked past #56.
Passive crossovers are not simple, and the components are not cheap.
It would work, though I have no recommendations, and prefer amps and processing separate from the enclosures.
Art
