1) Service personnel based outside Scotland during the last Holyrood election and subsequently assigned to Lossiemouth took no part in the democratic process which resulted in the recent tax increase. The 'democratic choice' argument advanced by an earlier poster is entirely bogus.
2) The fact that the proceeds of the tax rise are being used, in part, to fund a public sector pay rise makes the issue doubly toxic given that service personnel will not be included, Armed Forces pay being a matter for Westminster.
Now that the matter has been brought to light I can't see it passing the political 'smell test' and some kind of fudged solution seems inevitable. One would hope that any funds used to compensate personnel stationed in Scotland will come from Holyrood's newly-enlarged coffers and not the MoD's already-stretched ones.