Hi Dadla,
In which case, like the Perrys' Boer War British, it would have been better to have figures with both instruments.
I suspect if the unit is a Rifle regiment (or is a PIFer), I'll go for the Bugle, otherwise I'll just have the drummer in a unit.
It's just of those things that bugs me (and is a small thing that I spend time trying to figure out of all proportion to its importance..)
Tim