Works for me. 2HD it is.
We know Dex is 15. Skeletal warriors get +4 Str, so maybe Str 14 (or compromise to 12). Going for skeletal warrior lite, I'll give +2 to Wis but not Cha.
Str 14, Dex 15, Con -, Int -, Wis 12, Cha 10?
I'd be OK with giving them a higher Strength than that. How about basing them on a typical human fighter with the elite ability array?
Elite Array: 15 14 13 12 10 8
Typical fighter: Str 15, Dex 13, Con 14, Int 10, Wis 12, Cha 8
Let's say they have a skeleton's +2 Dex racial bonus, plus a +2 Str racial bonus (half the skeleton warrior's), that would make them:
Skelos: Str 17, Dex 15, Con --, Int --, Wis 12, Cha 8
Furthermore, since the were fighters of at least 4th level, they could get an ability increase from their HD. If they put that in their Strength it would increase to 18, but I think I prefer Str 17 for them, since they've evidently lost some of their hit dice as they have 2 Hit Dice, not 4+.