My experience with friction shifters (back when they were all we had - and for many years afterwards) was that you wanted to use the shifter made by the same manufacturer as the rear derailleur. I don't know if it was because of the size of the barrel around which the cable wound on the shifter, but the shifting always seemed smoother and more predictable when I mated them like that. It could just have been a psychological thing...
I'd say that this can be attributed to never having tried Simplex Retro-Friction shifters. They do not have enough wrap for 10 speed and up systems but will 6 speed systems and probably 7spd but I'm not sure about 8 or 9spd systems.it's a rule.
or just aesthetics, which has its own level of importance.
The Simplex shifters out perform the standard Campagnolo shifters by such a large margin that I see no good reason to use them just because they say Campagnolo on them. And if that's the only reason not to use them the old trick was a set of these over them.it would bug me. but, to each his own. i'm sure they feel nice.
is your rear brake cable just too long, or should you route it under the front cable to keep it down?