The method I’ve seen be used by those exploiting resetting war score progress involves having two alliances and at least one secondary account.
Whilst all the active accounts sit in one alliance winning a string of wars the second account sits in the other alliance deliberately losing wars. Once the alliance hits the max win ratio in one alliance and the other is at maximum lose they then switch around with all active players moving to the alliance with the low score and sending the dupe to the account with max win ratio to then lose a load.
The difference between having an alliance with a win record of 0 and +10 is 27.5% higher war score - this increases even more between a win record of -10 and +10.
The differences between roster strengths becomes even more pronounced than this as let’s say an alliance gaming the system has their war score modified by -20% and the other alliance playing properly is on a +10% modifier. The relative difference between their actual rosters without a modifier would be much more than a 30% difference.
The fact that war score is mainly irrelevant as something like a 30% difference in the strength of the two alliance’s war rosters puts the weaker alliance at a significant disadvantage based not on a genuine match-up but one alliance gaming the system to fight an alliance much weaker than themselves.