Having read and researched in advance, I'm sure you already know that everyone's profile is different; just as different lenders like different profiles. Unfortunately, at times it can seem as if there is no rhyme or reason, though folks have gotten pretty good at making assumptions about most lenders (Discover not included).
With scores in the low 700's, there are clearly sigificant negatives on your report. Have you looked at your reports recently? If so, I'm betting there are more than just a couple of late payments. And, if I'm wrong, I assume they are either recent, severe or both. If you provide more detail on the negatives, we might be able to provide some feedback.
This is usually why I don't post in public forums because people will try to pick your comments apart. Ok... I meant no derogs as far as BK's, collections, charge offs... Those kind of negs. I have 2 late payments on a Target card from 3 years ago. 2 30 day lates 4 months apart. I had 2 homes. 1 in California and 1 in AZ. I was moving to AZ full time and closed out my credit unions in California since they were just local to Sacramento. Now... If you think those 2 lates are the derogs they're trippin on then so be it I guess. Their reply message didn't mention payment history. They claimed too new of an acct and I call B.S. cause there are quite few people on all these forums applying same day with a 660 score & getting bigger credit lines. I have experian, transunion & equifax credit monitoring. I flip houses and I watch my scores like a hawk and especially since I was just in escrow. I also have identityiq and creditwise.
You appear to be looking for an argument but you wouldn't find one here. I'm simply trying to understand why you were approved for such low limits and the two 30 date lates would have had an influence even if NFCU didn't mention it. Payment history accounts for 35% of your FICO score so its the largest factor driving your scores.
None of those sources of credit scores appear to be FICO scores, except for Experian. They all seem to offer Vantage 3.0 scores.
I haven't read anything indicating people are trying to pick your comments apart. Like you, we're simply trying to determine the likely cause of the toy limits. Beyond helping you, it helps establish evidence helpful for future applicants.
As I mentioned earlier, I think you may need to revisit your reports. My TU FICO 8 is 723 (NFCU pulls TU for new CC apps) and I have a LOT more late payments than you (>25). And, if I recall correctly, six of which were 90 days late (most recent late was over 4 years ago). So, if your score is 710, something else must be going on.
This is usually why I don't post in public forums because people will try to pick your comments apart.