Why is it so difficult to re-assign a midi software instrument track to an external midi devicessign

I use external synth's a lot for example Yamaha MU80, Roland JV-2080 and Yamaha PSR 9000 predominantly to gig with and Logic really is an awful environment for this kind of work. I have to revert to using Sonar in windows which is so simple when it comes to being able to globally assign multiple tracks to external midi devices and also maps instrument definitions for voices easily. In other ways Logic is superb and in my studio environment is a truly great tool but for external midi it really does suck. Please Apple and the Logic development team, I beg you, give us better external midi instrument support.

I do not want to have to create a new external instrument track and then move midi data to to then trigger the instrument. Just a simple drop down to switch and existing software instrument track to external device please.