To see how much a difference pace can make, here’s how McMillan’s teams ranked in points allowed per game/points allowed per possession:
2000-01 SuperSonics: 24th/24th*
2001-02 SuperSonics: 12th/17th
2002-03 SuperSonics: 6th/17th
2003-04 SuperSonics: 24th/27th
2004-05 SuperSonics: 13th/27th
2005-06 Trail Blazers: 18th/28th
2006-07 Trail Blazers: 14th/26th
2007-08 Trail Blazers: 8th/17th
2008-09 Trail Blazers: 4th/13th
2009-10 Trail Blazers: 3rd/15th
2010-11 Trail Blazers: 7th/14th
2011-12 Trail Blazers: 18th/23rd**
And his teams usually perform well offensively. After all, if his defenses do poorly, there has to be some reason his teams win more often than not.
There’s plenty of variation in rankings for McMillan’s teams offensively (using points scored per possession) — 10th, 5th, 19th, 3rd, 2nd, 30th, 20th, 14th, 1st, 7th, 10th, 11th — but they certainly skew to the positive.