I know you are all-in for NU, you've proven that, but you asked above why it will be difficult to get good players from the portal...
Its because the Covid year is gone - there just aren't going to be too many grad transfers out there. If they got redshirted and graduated on time then they'll have another year of eligibility. Otherwise, they'd need to graduate in 3 years. If they're smart enough to do that, then we have a great shot at them, but how many are there? And how good are they? Not many talented Ivy League guys get redshirted as freshmen, for example.
The underclassmen we can pursue are most likely freshmen and sophomores looking to step up in competition, a la Mullins. Or sitting on the bench at good basketball schools... but we don't get many/any of those. We can't go after most upperclassmen, because of admissions policy on transfers. (Unless that rule was recently changed - but I'd be surprised).