"Scores Wounded" - A bit awkward, but I suppose it would mean that there are a lot wounded (as a score = 20)
"Numerous Wounded" - A certain number wounded, but the number is uncertain at the time.
"Countless Wounded" - Means that there are too many to count, this is a bit heavier weighted then numerous.
**It really depends on the sentiment of the sentence and the idea you're trying to convey. Personally, I wouldn't use "Scores wounded," just because that's not how I speak the language, but depending on the sentence and bigger picture it could work. :)