There are several reasons why blobbing your army is the most common tactic.
- Big blobs are hard to stop. It requires your enemy to blob up to stop you.
- Big blobs are less susceptible to loss of a few nobles who fall behind. Two out of 20 is no big deal. Two out of 5 is a significant loss.
- Big blobs take less losses. Two equal size armies meeting in the field will both take heavy damage. A huge army meeting an enemy half their size will suffer much lighter losses, and be able to continue on for longer.
- It's getting harder and harder to find people willing to be generals and marshals. And even harder to find willing people who are good at it. It's already difficult enough to find one good general and a good Marshal/VM pair. And you want to find four competent pairs? Not gonna happen.
If you want the big blob theory to not rule the warfare aspect of the game, you have to address all of these issues. The last one is perhaps the most difficult, and probably the most important.
