i'm not quite as advanced (researching midevil now), so not as much troop space (65), but have had excellent success with 5 comps (first through the breech behind a wall-miner), 16 bowmen (as defensive infantry spawn), and 5 raiders--coupled with a timely sabotage when needed. this shot me straight through the 600 medal range in a few hours (and now i'm out of my league), only needing to deploy reserve merc armies once or twice. i'll experiment with first-aid rather than sabotage, as noted by Damascus, as it's cheaper and quicker to build.