No, you can't count
There are thousands of retired generals. While it's true that active duty officers (not just generals) are prohibited by the Uniform Code of Military Justice from criticizing the civilian leadership, that doesn't apply to the thousands of retired generals and admirals. Out of those thousands, some 6-8 (including Wesley Clark, former Democrat candidate for president) have come out against Rumsfeld. That's a miniscule percentage. Many others have come out for Rumsfeld but you don't hear much about them because that doesn't fit the agenda.