I'm thinking the way byrdj is, viz., someone is looking to meet some environmental emissions compliance standard but hasn't bothered to tell the OP this...then again, depending on where in the world the plant is located emissions compliance may not even be on anyone's radar...and the info supplied remains light on specifics.
As to starting diversity, the OP seems to indicate the desire was to change ALL compressors to electric start, which would not affect source diversity at all.
Lacking a valid and compelling reason for doing so, I'd see no advantage whatever to changing start-up methods from gas to electric.
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]