Ah, when you say "using the target of target function" you mean you have your main targeted the whole time and just have the "cast on target's target" checkbox enabled in the game settings?

I use "/assist <name>" commands instead. The "/interact" has to be a separate button since it'll take a brief moment for a character to switch target and the "/interact" is instant and may try to interact the previous target. It's possible to do "/assist <name>" on keydown and "/interact" on keyup, that's enough separation.

So you would make two macros that works like your follow-the-leader macros. One that works like your /target lead macro, but says "/assist MyLeaderName" instead, and one that works like your "/follow" but says "/interact" instead.

Note that you have to be grouped for /assist to work. The /assist command will be ignored if you're not grouped.