Lots of little anachronisms in the battle scenes -- watches, sneakers, etc. that didn't get removed in time -- but the basic tactics depicted weren't too far out of whack. YOu don't get to see a lot of them developed because it is easier to film close-ups of the hand-to-hand.

Gladiators were NOT fighting in the coliseum-style fashion depicted in the flick. They were mostly paid entertainment for funeral games at that point. Moreover, the goal of the Spartacus groups was to escape Italy and take over some terrain that they might defend -- Sicily being a prime choice since it was full of fellow rebellious slaves and had a history of giving Rome grief even before Spartacus.

The revolution was doomed from the outset, though, since Romans never gave up on a problem and would work for generations against an enemy if needed. Carthago was not Delenda in a day. Crassus mostly let the Sparticans starve after walling them off in the toe of the boot -- but that makes for poor film.