OK, this brings up another thought... Would the transmitted signal
from antenna a, being close to b, cause b to have a high swr and vica
versa?
________

Yes. Depending on the single-radiator pattern shapes and installation
geometry, mutual coupling between two adjacent antennas of the same
polarization, and cut for the same frequency can be -10 dB or less. An
"apparent reflected power" of -10 dBc = 1.92 SWR to each tx, plus
whatever SWR each antenna system has to the tx hardwired to it.

This performance may be OK for amateur radio, but not for broadcast
stations. To avoid this situation, broadcast system designs using
several r-f amplifiers combine the amplifier outputs to drive the
antenna system from a single set of terminals.

The antenna system design itself provides omnidirectional or
directional coverage in the horizontal plane as needed, but it is
always fed from a single set of terminals.