I agree with Yilmar, except I might push it to 25 just because it seems 'right'. 6 wide is probably the best way to start games Giving you 4 ranks and 1 guy spare, which will probably increase to 2 since Im guessing most units would have a charcter in. That would mean you can take 3 casualities before losing a rank bonus (you dont need complete ranks anymore, just 5 or more). The additional benefit of having that slightly larger unit (over the normal unit of 20) is that if you do get into a fight with lots of attrition or against an enemy with more ranks you can do one of 2 things: increase numbers of models in the front rank to kill as many enemies as possible (eg if you are fighting something like a 10 rank goblin unit you need not worry about losing, but a few extra ranks arent going to help... you need to get on with killing as many as you can as fast as you can), alternatively you could reform into 5 wide to give yourself as many ranks as possible (if you still have 25 models thats 5 ranks, few enemies will have that many unless they are tarpits). This is good if you need your saurus unit to hold for reinforcements against a strong enemy unit (eg you get hit by 15 chosen... you arent going to win so might as well make it as hard as possible for them to beat you... while you bring up something capable of beating them), or if fighitng a unit of 30 'men/elves' in 5 wide formation: having 5 ranks means you need to kill off 1 rank more of them then you lose and then you've got rid of their steadfast.