Not interested enough about Arsenal so can't be botherd to check, but you're probably right about how long he was the largest shareholder. Morale issues aside, but the fact remains Arsenal had the Roman A. level money available for them as Usmanov wanted to purchase the club wholly and spend huge money to bring success to Arsenal.
But like you said, the other owners chose rather to concentrate on boardroom and ownership battles, and sacrificed sporting success on this altar. So they de facto let the club, manager, players and fans down. But you can't cry poor and lack of silverware compared to others like Chelsea when it was your own making.
Good for rest of the league and European teams, who got to enjoy the trophies, while Arsenal chose to "enjoy" higher moral ground, I suppose.