How to avoid units bumping each other on the way to attack?

I keep seeing this... It is more frequent with heavy cavalry, but can also be seen with infantry, like Eagles..

Essentially, when there is a large group, the units keep bumping into each other and there is definitely wasted time when they chase units... I almost always Patrol in and never target any one unit... Still, the units bump, they stop for a sec, then repeat...

Now, if the opponent is using 6 hit and run, with archers or Xbows, the units take a lot more damage than needed... Same thing with villagers... Invariably, the vils take one or two hits less because of this and survive... Any ideas on how to avoid this?