Nisei Division is just not very good.
There, I said it. But it's worth discussing why it's not very good, and thinking about maybe what it would need to become decent.
Any discussion of Nisei Division needs to start with a discussion of the psi game. Each player secretly and simultaneously spends 0, 1, or 2 credits. I'm going to repeat that, with added emphasis: each player secretly and simultaneously spends 0, 1, or 2 credits. This is crucial to the function of the game--the players are not simply choosing random numbers, because in Netrunner, every single credit matters.
So, spending less money is better than spending more money, all other things being equal. At the same time, though, the benefits of winning the psi game (or the penalty for losing) is typically so huge that it is worth the extra cost, if it works. This leads us to a strange situation, something vaguely similar to the Battle of Wits scene from The Princess Bride, with one crucial distinction--the corp has to make the values different, which is much easier than making the runner's task of making the values the same, giving an edge to the corp.
However. In some cases, the runner might be able to trigger the psi game repeatedly, or the penalty for losing might not be particularly severe--taking 1 brain damage from a Cerebral Cast, losing an early run to Snowflake, or letting the corp hold onto The Future Perfect when they don't have a scoring remote are all places where the runner can afford to lose the psi game. In this situation, an experienced runner will almost always bid 0--if the corp bids 0, they win, and if the corp spends 1 or 2 credits, they've at least forced the corp to burn resources.
This is where Nisei Division is theoretically advantageous. Now, instead of losing 2, 1, or 0 credits from a psi game, the corp might lose 1, break even, or gain 1 credit. Suddenly, the "always bid 0" runner tactic doesn't work, because the corp can always spend 1 (because they get it back), winning the psi game without cost. Betting randomly makes some sense now-- Nisei Division will break even in credits in the long term, while the runner will lose a credit per game on average.
This means that Nisei can afford to play a lot more psi game cards. Snowflake? Put in three of them. Cerebral Cast? Why not, put in a couple. Clairvoyant Monitor? No, that one is still pretty much terrible, leave it in the binder next to Bullfrog. And of course, the classic Jinteki cards The Future Perfect. Caprice Nisei, and Marcus Batty.
The problem is that this doesn't lead to any sort of real strategy. Cerebral Cast needs Scorched Earth to make both the brain damage and tag painful, but Caprice Nisei does nothing to help a kill strategy. Even if they break it every time, Snowflake is just a slightly cheaper Wall of Static, and there's not much point in using Marcus Batty to trigger an "end the run, maybe" subroutine. And because there aren't enough psi game cards to fill a deck, any Nisei Division deck will need to start pulling in cards that would fit better in Personal Evolution or Replicating Perfection--and at that point you might as well just play one of those IDs instead.
For Nisei Division to be able to stand up as a decent ID, there need to be more psi game cards, cards which trigger psi games more than once, and they need to have some internal synergy. That could happen--but I sincerely hope it does not, because reducing the outcome of every match to "who plays psi games better" would be a sad thing to happen to this game.