I know that trick, I used it a long time ago on Europa Barbarorum I, EB 1 have units with high devend an low attack if you do the same thick agianst units with high attack and a low devence you will get slaughterd ( I used it at rome Tw with a group of roman legonair soldiers agianst warband archers and the archers destrooit my unit in just 3 seconds).
If you unit is stronger they can't defeat there enemy quick because there is not to muts space to do so, if you have for a group of 120 men perhaps 30 man are fighting and the rest waiting in the ranks to replace the losses. This thakes time an your unit get tired. but to move quick trough there ranks you will lose some man but you will then be posible to use the advantige of youre troops with geat effect. use it only when you have better troops than your enemy or you will get a slaughter.
