I think it is important to decide which players you want to target early and try not to waver unless it just looks impossible. With a B prestige it's hard to beat an A+ unless you have a really big AP and Preference advantage. I usually pretty much know who I am going after once the first cycle has processed. Sounds like you are pretty good at picking who to focus on though.
I have this saved from a long time ago. I am not 100% sure this is right, but I have no reason to believe it is not right. This has to do with prestige.
Basically if you were an A- prestige, then an A+ prestige would only need to do 71% of the AP/HV/CV you would for the same effect. But some A+ teams are like A+++ so it could be even lower odds.
So, looking at this, if you are a B prestige, then an A prestige would only have to do .87/1.31 or 66% of the effort for the same effect - all other things equal.
So you want to try to look at how many openings the opponent has, see if you can detect the battles they are in, and things like that as well. If they only have 2 openings and you have 5, then you could go with 80AP per cycle, and their maximum would be 60.
| A+ = .71 |
| A=0.87 |
| A- = 1 |
| B+ -= 1.14 |
| B = 1.31 |
| B- = 1.5 |
| C+ = 1.72 |
| C = 1.97 |
| c- = 2.25 |
| D+ = 2.56 |
| D = 2.9 |
| D- = 3.27 |