Two motors on one axis EMC

Hi Group!

I am planning on building a large Gantry 3 axis mill
and have to use two motors on X-axis, and maybe
also for the Y-axis.
Is there a way to configure EMC to run two servos
for one axis in a master slave combination?

I am also preparing this 3-axis machine to add
a 2-axis rotary spindle, to get 5-axis motion.
If I need 2outputs for X, and 2 for Y and one for Z
plus 2 for the head, a total of 7 motors,
Is EMC limited to 6 axis or can I configure 7?

Best Regards!
Lars Levin, Sweden