With 24th century LCARS, I believe every console can be reconfigured (if I understood Sternbach & Okuda's TNG Technical Manual). So it might be possible to run Conn control through Tactical, or any other console.
Well there seem to be some restrictions (even if it's just a restriction in the sense of being a lot of time/effort to get around it) since there's a great many functions that seem to only be available from consoles on the bridge, battle bridge, or engineering. Within bridge consoles, though, yeah, that's my understanding as well.
But Paris/Geordi didn't seem particularly skilled at manning Tactical, and while Worf did some early duty at Conn we never saw (to my recollection) Yar or Tuvok take the helm or any hint they were particularly good at it.
And I want different Tactical officers to have more than 2 different skills to distinguish between each other, and I definitely want Flight Controllers to have more than 1. But I don't want so many that it becomes overwhelming/unmanageable. 3 seems like the magic number.