The addition of ARMs makes missing functionality obvious; allow radar emission selection

The current iteration of ARMs is problematic in that we cannot target priority threats due to no control over which radar emission the missile is to target primarily. This means that if there is a (example) gepard in front of a crotale, the gepard will generally be prioritised if it is closer. Whilst we do not necessarily need a full implementation of elint systems (though that would be nice), the option to direct the missile towards a specific emission would make using the weapon less frustrating.