R2-D2 is run over Chopper because it's better to maximize your own card draw than to soft punish opponents for drawing. It's a combination of the fact that the cards in your command deck are always going to be useful (that's why you put them there) whereas denying the opponent a random draw may not be that valuable, and something I call the browbeat effect, where it's better to guarantee an outcome than to let your opponent choose an outcome that benefits them the most based on information that is hidden from you.

If you want to run a 3 point figure that messes with your opponent's command card flow, Mak with Intel Leak and Strat Shift is the much better choice.

But Chopper can do other things than just zap through a terminal, such as pushing your own or opponents figures into and out of position. I once used his CC to push a figure forward 4-5 spaces into position. He's often a terminal hugger, but he's so much more.

In a direct match-up R2 vs Chopper in a standard 3 round game: Chopper will zap R2 once per round. R2 will heal himself and draw a card each round. R2 won't die in these 3 rounds. When R2 moves after Chopper turn 1, then Chopper won't zap that round. Maybe R2 will even take the damage instead of the card draw once per game, maybe turn 2. When it's the last turn, R2 will take a card and move away from the terminal. Then chopper AGAIN will not zap.

R2's only problem is his speed, which is negated by Hera. In a Merc list, Chopper can have Headhunter, which starts a completely different argumentation. But then he is one point more ...