I don't like the 30-pitcher tiers because, let's be honest, there aren't enough decent pitchers to go around. There were 30 guys last season who pitched 100+ innings as a starter with ERAs above 5.00. The Royals had two well-pitched games from Adam Bernero, but the other 15 guys they sent to the mound to start were just awful. It's arguable whether the Royals even had a #5 starter on the roster. What they really was a collection of guys who shouldn't have been pitching in the majors.
I'm an absolutist on these things. A #1 for me is an ace, a guy who can dominate year-in, year-out. A #2 guy is someone who can keep his ERA south of 3.50 most seasons and a #3 guy is one who'll fall in the 3.50-4.00 range most seasons. ERA+ might be a fairer way to group it, but I'd have to look into where the lines of demarcation should be drawn for that. Obviously no one stays precisely within those confines all the time, but what Harang is, most seasons, is a guy who can take the ball and chew up a ton of innings with a solid, but unspectacular ERA. I'm thrilled the Reds have him. In general, I love pitchers who can do that. Yet I don't want to see the team pay him like he's a superstud. He's not. Among other things, the Reds don't need to be inflating the market for the class of arms they need to be stockpiling. If you're going to start paying $10M or more for guys who can keep their ERA just below 4.00, then I'm not sure the Reds have any real alternatives to crossing their fingers and hoping that Homer Bailey, Johnny Cueto and Travis Wood all turn out to be studs and arrive in the majors at roughly the same time.