They do not move around because the bots create their own nodes. Thus when they 'wander about the spawn' they create dozens (or in my experience, hundreds) of nodes in a very tight area. These nodes are all interconnected.
The problem of course for playing with Realbot is that you must first play it with NO bots and simply walk around the map
for at least 15 minutes from both spawns, to every important area, along every hidden path, etc.
I play Mindmaze2 with 7 bots (prior to the current version I was able to play with ~23) and it's still rediculously laggy.
^ That's a picture of Mindmaze2.
Before I ran a single bot through the map I walked
everywhere. I criss-crossed the ground at least 60 times in two different directions, I circled around every pillar, box, and ramp. I went through each tower several times, and I did every possible route on the walkways.
Unfortunately, in hindsight I should have double-noded the walkways (walking along each EDGE to try and fit 2 nodes) so that they would have a higher chance of being selected. The AI very rarely goes to the upper levels, but after playing CT many times, if I switch to T the AI is smart enough to follow me up to the highest walkways and chase me through towers.
I am going to re-node it with that system in mind, because currently its rather rediculous that every game consists of a single ground rush, and possibly a few bots being smart enough to run up and pick off the others with altitude advantage.