Really cool idea and looks pretty cool! 4/21 buildings saved lol I'm going to try and do better!
Edit: 11/21
Edit: 14/21
Edit: 21/21! The strat is to always be moving. Move one firetruck and then the other and never be sitting still doing nothing. Also ignore the top town as the fire reaches it a bit later so you can use your first two fire engines to slow the fire until you can get a third and then one of your old ones can go defend the top village while all new ones defend the bottom one. Use planes the moment you get them.
This was a really cool game and I enjoyed playing it! I like the strategy needed to save everyone. It must be very stressful being a real firefighter.
Good job!