Hi! I'm new, and Im really enjoying multiboxing in classic for the first time in my life. Running two wow-clients on the same pc.

I am not very tech-savy, but I usually find my way around problems I encounter. So here is the description of what I need help with:
I have a warror tank main, and a feral druid alt. When I press my #1 key, my warror uses his /startattack macro, and my cat uses this macro:
/startattack
/cast Claw

What happens though is that the druid targets the nearest mob (usually correct) and stops following the warrior. I counter this by having a target and follow macro bound to another key, but I was wondering if there are more elegant ways of doing this?
I was looking into focus and assist, but I cant really understand it. It seems like the focus function isn't implemented in classic?

Thank you so much from a multiboxer newb