But it can't exist any debatement about how building a player that is cost effective that sees a reduction of ID to such a low level
Defenses are good to train to high level in any cost efficiency model
The key to BB is creating a salary efficient team, not running a particular tactic. Yes, in D.III where most of your experience is, 10 ID rather than 12 ID may make a big difference. Against 19 IS, it’s negligible, just as there’s not a dramatic difference between 3 ID and 5 ID against 12 IS.
Take my starting center, Macaldo, for example. His primaries are 19/9/18/4. This allows him to score efficiently (forcing opponents to think twice about running a 3-2) and rebound against even NT level bigs, while costing me a mere 85k a week. To increase his ID from 9 to 12 (which would do little to slow down elite bigs), he would cost over 120k a week. To get his ID to 18, where he would be much more effective but still struggle with a lack of SB, I would have to pay over 250k in salary.
I’ve found that investing in other areas (RB, OD, PA, etc.) produces a much more effective team.