If the 4600 has the v2 processor (highly recommend if you plan on really using it) then it can do documentation along with the auto trac. 

And Automation 4.0 is the top level package that has all the toys. 

Premium activation is much less $$ and has lifetime section control, row sense, etc but not the turn automation, implement guidance, and things like the above. 


You can run the 2630 in the corner post but it will likely have to do all the precision ag functions. 4600 will only do tractor monitoring like lights, hydraulics