If you waqnt to use Maverick then you don't need any script, you can do that just with waypoints. I can't answer your question about mando missiles since I've never used them, but I can tell you how to make them fire to those tanks. It is very simple: just make sure the two planes are in different groups (i.e. they're not connected by the group blue line), and create a DESTROY waypoint for each plane attached on all the T72 (it is better you make each plane engage 2 T72's each): to attach a waypoint to any unit just double click on it when you place it instead of double clicking the map. You will know that the waypoint is attached if you can't drag it around the map. Remember that the waypoint
must be attached in order to work. I took a screenshot of the editor, so you will understand better because I know that these things can be difficult for beginners. Sorry for the Italian language but I forgot to change the language before launching ArmA, in any case "DISTRUGGERE" means "DESTROY". Also remember to place the planes far enough to make them spot the enemy and react properly selecting the maverick and firing it, and also set the unit property as "flying"
EDIT: I discover it doesn't display the waypoint names in the picture, I don't know why, in any case I think it can help you anyway