Well that's an unanswerable question, in my opinion...
It all depends on so many factors! like:
1) your warband
2) the mission objectives
3) the scenery you have at your disposal for cover or shooting positions
4) the enemy you are facing
...and, the last but not the least:
5) the way you want to play!
If you have 2 youngbloods facing 4 beastmen but you want them to charge anyway, then DO IT! just for the sake of it! just for "la beauté du geste"
(even if they are going to be turned into a reddish jelly)
here's what I found a few days ago:
http://www.mordheimer.com/tactics/tactics.htmI read the tactics for Reiklanders and I found it quite boring because there was nothing we didn't already know. See for yourself...