I'm doing 4 towns as well. My secret is synchronization. What you do in one town you do in the others.
I just started the 4th town recently to find out some stuff like:
- what's in the Yearbook from the start (and what column does it appear in)
- is there some trick to get Sideshow Bob on Android (no luck with that so far).
It was a major pain catching up town 4 to the point where it's just one more set of actions to repeat (Where's Maggie / tap buildings / event activity / send characters on tasks). I still make mistakes sometimes though. Yesterday I forgot to tap out the Event characters in town 4 when I had run-over: I only needed 4 Vinyl Records to complete the round and get the prize but I forgot to tap that town until all of the characters were finished with the task. So then I had to send fewer characters on the Event task for the next round to keep it all even. And it throws me off badly when one device gets 'stuck' and the game won't load. (Yes, each one is on a different device. Can you say "Special Sale Price"? Yes you can...)
Actually... I'm not quite ready to start KEM farming in town 4. I'm trying to build my Blue House farm up a little more before I start so I won't run out of cash before the end of the day.