Pres. Clinton did it "en masse"......Pres. Bush (W) had it done by April.....most have replaced all or almost all by April......That is what the link says....It is March, 

 Pres. Trump has done it "en masse" and a month early....he is following a 36 year pattern.

He is in a hurry, he has a lot to do....a big agenda, cleaning up 28 YEARS OF LIBERALISM!!!

Bush SR.....Clinton....Bush W....Obama...28 years of Liberalism !

For the record, I wish they Kept Ms. Loeffler....she did an awesome job and will be hard to replace, but that's politics.