You raise a couple of interesting points.
The reason that the B1G is the best basketball conference in the country is that it has the best group of coaches. College basketball is "coachcentric." The B1G has terrific coaching talent: Crean, Boelin, Painter, Izzo (of course), Bo (of course), Carmoudy, McCaffrey. We have Tubby. These guys can recruit and coach at high levels. Tubby hasn't shown that here.
Coleman dribbling a ball of of his knee is secondary. It's about getting the best players and putting them in positions to succeed. The best coaches in the B1G at those two functions are Izzo, Ryan, Crean, Painter and Boelin. Tubby is in the second division.
Not sure what Carmody has done that Tubby hasn't. He went .500 in the Big Ten once, giving him a tie for 5th place in the conference, which was also his only conference finish higher than 7th, and of course he's also been at Northwestern about twice as long as Tubby has been here. So I guess his highest finish is higher than Tubby's, but Tubby's also gone .500 twice already in half the time, and made the tournament twice (could have been three or four times without all the injuires IMO), which Northwestern obviously hasn't done.
You also say "of course" after Bo Ryan, and while he's done well for sure, he sort of seems to have plateaued. He has four Sweet Sixteen finishes and an Elite Eight finish, as well as three Big Ten titles. Two of those Big Ten titles were in his first two years though, and we all know big accomplishments aren't as impressive when you do them with the previous coach's players.
That Elite Eight was eight years ago now, and it just kind of seems like Bo Ryan is good for a given level of success, a Sweet Sixteen, and not much more than that, consistently good, but not great. He also inherited a program that made the tournament the previous three years to his arrival, and only two seasons removed from a Final Four, much better than what Monson and Tubby found when they got here.
Tom Izzo has 7 Big Ten titles to Bo's 3, and has more Final Fours than Bo has Sweet Sixteens, and of course a national title. I think Bo has a better regular season record than Izzo does, but I'd definitely take some 5th, 6th, and 7th place conference finishes in exchange for more conference titles and those Final Fours. Even if you only look what the two have accomplished since Bo got to Wisconsin, they are still equal in conference titles with 3 each, and Izzo has 5th, 6th, and 7th place conference finishes in that time period, but of course much more post-season success. Izzo and Bo are both good coaches, but I'd take Izzo over Bo any day of the week.
As far as single season success goes, it also looks like Beilein and Crean could both accomplish more this season than Bo has, at least in the post-season. The Big Ten is very strong this year, so I doubt either of them will match Bo's best Big Ten record of 16-2.