You're getting a variety of answers because people have different viewpoints. I gather you're in training and the "previous plane" didn't survive the experience.

If you had bought the Sig Kadet Senorita, which sells for about $56 some places, your kit would have been designed for 3 channel operation, no ailerons. That plane has plenty of dihedral and a large, flat bottomed wing. It is very light.

The Tower 40 is a fine four-channel airplane, with less wing area and higher wing loading than the Senorita. It's designed for 4 channels. Opinions vary. Mine is, you made a mistake selecting a 4 channel plane for a 3 channel radio. I suggest you eat it, and either buy a 4 channel radio, or a Senorita kit.

I doubt you'll have "more control" with either the rudder/elevator or aileron/elevator selection, because you'll be missing something either way. If you insist on doing it your way, flip a coin. Or try both ways and see which way you like it best.

Good luck,
Dave Olson