MSU stands for Multiple Small Units. The strategi can be easily summarized as "flank 'n' flee". You have, as MSU means, many small units instead of some big and you use their high movment to flee with some units and countercharge with others. Essensially you are picking your fights much more than with "regular playing". That's because small and cheap units allow you to flee without taking a too big risk, and the size of the units makes it easy to manouver.
It's a playing- style that demand some skills and training as I see it. You have to be very careful not be charged by big infantery blocks or heavy cav for example.
I think the MSU is the way to go with ogres because it takes use of our high movement, and that I think that having Ogres in big regiment (thinking of IG and Bulls mostly since all other units are generally being used at the min. size) is not cost- efficient. They don't get their points back IMO! And when it comes to take charges with, my experience is that they often loose because they haven't any static CR. It's no great plus to have Ogres in big regiment sinve you get no rank bonus and your manouvering is being halted because of the size. The enemy will also have a more juicy target to hit on.
In MSU there are no juicy targets for the most, and the small 3- ogre unit take advantage of the high movement and manouvering to get in the right positions. Ok, they have no static CR of course, but to the big units have that? No, mostly not (except for banner) thay have no ranks and even their outnumbering is hard to hold on. 6 Ogres give 18 in US and most infanerty blocks are 20 or more. Though will the ogres the ogres take some wounds, but then you haven't taken in to count the wounds the Ogres will suffer from magic and shooting. No more outnumerbing probably. And with big units you certainly wont get in any flank charges.
I have problems seing the point of having Ogres in rear rank not doing anything. Ok, they give one of their comrades +1 S on the BC, but I would have prefered those 3 extra attacks.
Hehe, I suppose I got a little "over" the topic here, but I hope it's worth something

Tor- Eivind.