besides the fact that i beat a french player using England in MP once, that normally doesnt happen in vanilla but the addition of the Channel islands really drastically increases the chances of England beating France. now im not saying this isnt good, but some of the National ideas are seriously overpowered. the gain of prestige/naval tradition/army tradition has always been a very delicate balance. 90% of the cases, naval battles are determined by admirals (you only certainly win a battle with 4x as much ships). In one case, a bad admiral from my ally portugal led an attack on Ming ships charged by a super chinese admiral. we had 2700 ships and he has 1200 ships. We lost 1200 ships and he lost 600 as he retreated into port. admirals are easier to make godlike in WWM since the ideas boast more extra fire and manuever for admirals, fire naturally causes more victims during fire phase, and manuever causes more enemy victims during fire phase as high manuever values of yuor own, and low of the other, cause the enemy ships to crash into/fire at each other during phases. from NI's alone, in WWM you can get 50% more naval tradition then normally would, not to speak of double the amount of manuever and +1 fire.
this is really just MP players fall over i think. fighting humans require a very diffrent aproach and knowledge is power, so MP players usually know every facet of the game and how certain things work.
im still in love with the WWM for the no PTI, for me its still the best mod in there. (especially so because the other ones alter the game even further) but i guess you can see me as heavily judging from an MP point of view since i never play SP anymore. but thats why i was developping the sister mod that only focusses on the map and additional countries/decisions events. further no integral change to the game mechanics as i kept running into heavy protests whenever i tried suggesting WWM for MP.