I thought I explained it well, I'll try it again. This time breaking it apart even using your interchangeable wording which I'm not disagreeing about the words, more about the overall meaning. It doesn't say Each friendly corps unit that spends, or anything along those lines. Just each time one spends an aim token which could be more than one. I'm not saying you spend 1 then gain 2, just saying spend 2 gain 2, spend 5 gain 5 as long as it is a friendly corps unit and the unit receiving is at range 1-2.
1. After 1 Friendly corps unit spends 1 aim token...
2. ... 1 other friendly unit at range 1-2 may gain 1 aim token.
Let's say I have 4 stormtrooper corp units, two of them has been given an aim token from Veers ability spotter 2 earlier on his activation, now I choose one of the stormtroopers with an face up order token and aim token.
I decide to use my first action to gain an aim token giving this unit 2 aim token. Then I use my second action to do a ranged attack on a rebel trooper range 2 away. I roll misses, so I use an aim token. (1.) (2.) I still have some dice results I want better, so I use another aim token. (1.) (2.) Which if given to the same other unit, it now has two aim tokens since I spent two aim tokens with a friendly corps unit and the other unit was range 1-2 away.