Which is best combination

I have Two Motors (A.C Squirrel Gauge I/M)which ratings are 60 HP out of which one is connected for VFD and another one is on normal operation.

Which are using for Air compressors(293CFM). my working pressure is 8-9Kg/cm2 (g).

Max pressure can deliver the Compressor is 10 Kg/cm2(g) only.

How to use these motors as combination.

For base load & Peak load ,how to use. Which is Economical combination?

My running hours / Day is 20Hrs.

I am very thankful to u for u r consideration.