4th axis rotary table setup

Morning all!,
I have a rotary table which is geared 90:1 that i want to use for my
4th axis. should I direct couple this or gear it say 2:1 . The reason
I ask this is i am concerned that if i use a Gecko 201 to drive this
with a 200 step motor then i will have something like 18,000 steps
per table revolution or 180,000 with the micro stepper and double
that geared ( have i done my sums correctly?)i doubt that my computer
could cope with this! What do others do?
thanks in anticipation
Mark