Airline with more than 3 fleet types

[Ocean1234]

Are you allowed to have more than 3 fleet types of your airline? My airline only has 2 fleet types (It is A320 fleet and Bombardier CRJ fleet)

[Jake]

You can have as many as you want to, but the golden rule is to have 3 or less.

A lot of useful information can be found in this thread if you want to take the time to read it: https://www.airwaysim.com/forum/index.php/topic,79048.0.html