As otter girl has so clearly stated BA have tried very hard to accommodate languages but the logistics of this are almost impossible.
In the good old days on Longhaul cabin crew who spoke French found themselves being rostered endless Montreal trips and in the end withdrew their 'flag'.
In Europe the crew will operate more than one flight per day as a crew on the first part to, say Frankfurt, they may have a German speaker but the next part is Pisa so maybe no Italian.
All airlines in UK will have the same problems and I bet when Alitalia fly to Sweden they don't always have a Swedish speaker!