It's difficult for northern teams to excel

Not impossible, but difficult.

Notre Dame and other northern teams start every season with 15 (+ or -) road games; and when it's finally far enough into March to attempt home games, there is a better chance to be playing with temperatures in the mid-40s as the mid-60s. 14 of Florida State's 16 non-conference games were played in Tallahassee with the other two in Tampa and Gainesville. Strictly from a baseball standpoint, which schedule would you prefer every year if you were a top recruit being courted by both ND and FSU?

It's hard for northern teams to attract a lot of top level players.

The 11.7 scholarship situation is discussed elsewhere in the thread. If I were Notre Dame's head coach, I would be spending the lion's share of that scholarship allocation on pitching. Mainieri's and Murphy's best teams had pitching. Lots of pitching. A rotation like Mainieri had with Manship/Samardzija/Thornton plus a couple of solid relief pitchers will be competitive.

Recruit pitching. Get one outstanding starter every year. Then find the scrappiest defense-oriented players who can afford ND and/or who can earn academic scholarships to fill the roster.