Well, the Engie bots loves to make concentrated nests, but yeah, their placement is very odd. Most actual players would put them behind map geometry or the like and try to cover choke points (eg. the main route to the second round 1 CP in Dustbowl). These guys just tend to stick them out in the open.
Plus they, from my experience, rarely upgrade dispensers and teleporters.
It still beats the Spy AI though. Granted, that class would be difficult to code to approximate human behaviour, but it is still absurdly easy to tell a bot Spy (usually on servers that impose class limits and/or Highlander mode). At least it can cloak, disguise, and backstab :V (originally they just revolver-spammed to victory).
Traded a scrap for a Backburner. Am pleased with this.
And thus we have another Frontburning W+M1 PyroSpeaking of Spies, defending Spy on Dustbowl and Badwater is just getting too effective. Backstab after backstab after backstab after Enforcer kill...easily racked up 30+ points in a single round. I have no idea why I haven't done this beforehand.