Understood. 25 TDs would put him too 30 in FBS. I don't know if the stats I looked up included bowls/championships or not. I would think Nebraska fans would be plenty happy with 25 TDs through 12 games. The post I quoted made it sound like 25 TDs would be the difference between 6 and 10 wins. I would think the number to watch is INT's. Keep it below 10 and 23 TDs would be pretty good right?
We'll have a new defense, and we're replacing a running qb with a throwing qb. We don't know what Langsdorf's playcalling breakdown will be. We don't know when the passing TD's or INT's will come, maybe 4 in some games and maybe 0 in others. You're asking about INT and TD numbers, I see more to it than that. But I'll eventually try to answer the question.
It's not wise to try to use statistics to describe two different situations, especially with a bunch of unknowns. But that's what I'm gonna do here. The prudent choice is to just say there's question marks, and save yourself an hour of time looking up numbers and posting on a message board. So take whatever is coming with a grain of salt.
The data
2015 NU - 458 pass attempts, 27 TD, 21 INT, we score 33 ppg, opponents score 28 ppg, TA has 129 QBR. What I see first and foremost is 27 TD's and part of the OP is about TLee having 25 TD's. Next I see 1 out of every 17 attempts is a TD, 1 out of every 22 attempts is an INT.
2016 NU - 399 pass attempts, 18 TD, 9 INT, we score 27 ppg, opponents score 24 ppg, TA has 124 QBR. So, 1 out of 22 attempts is a TD, 1 out of 44 is an INT.
TLee stats1 - 1 in 28 attempts for TD, 1 in 24 attempts an INT, 108 QBR.
TLee stats2 - 1 in 25 attempts for TD, 1 in 39 attempts an INT, 110 QBR.
The discussion
In 2015 we see a higher number of TD's and INT's per attempt, indicative (to me) of a more open and aggressive passing game. Either the pass playcalling, the QB decision making, or both were more aggressive, bigger risk, bigger gain. 2016 is the opposite with lower numbers of TD's and INT's per attempt. TLee's number indicate a more conservative approach. 25 TD's to 10 INT's would be a pretty big step up for TLee. An interesting side note is that for both TA and TLee their comp% went down from one year to the next.
Now to answer your TD and INT numbers question. 25 TD's and 10 INT's is only enough if our run game can account for TA's rush production and our defense is at least as good or better than last year. I don't see us being able to recover TA's lost rush production. I would not expect TD's and INT's to be distributed uniformly over the season. I would generally expect more TD's against bad teams and more INT's against good teams (generally speaking). I would not expect our defense to hold opponents to less than 20 ppg this year, so production has to come from somewhere to win games.