People say they like to PvP, which probably is true for some, but still one of the biggest movitator and cause of mercs are those Badges/Titles not limited amount of SW spots. I have this feeling that most of the low point easy win merc guild would magically (surprise, surprise) disappear, if Prizes were completely removed. Probably then only couple random e-peen guys or loners in their own or friends guild would be left in lower rankings... If people really love PvP, they will keep playing it even if prizes were removed.
Guild with multiple known taking-turns-to-drop-points alt guilds and wars where there is no enemies because point dropping are just low. There are still many guild having hard enough time to register. If people have patience they can at least draw purposely against point-dropping-empty-guilds instead of winning, to prevent them dropping points while still getting nice prizes.
They should make some changes like no joining new guilds withn a day after leaving combined with even amount of badges for everyone for participating regardless of merits/kills, so there is no need to be a top in noob guilds (extracting crystals only with all merit/speed upgrades is just a lol way to get 1st rank in SW without helping team at all). Even thought prize system is bit improved, more people get more badges and ranking less bugged than it used to be, seems only total merits matter anymore. SW is a team event anyway and should motivate people to play teamwork, not solowars (like some unnamed crybaby losers I tend to see ragequit time to time, when they cannot slaughter whole enemy team all alone with their class). Both winner and loser of course should get bit different prizes in this case or else it would provoke teams to just ignore defences and go for the crystal to end it quickly for easy prizes.
Another thing which could be used even alone or together with earlier suggestions and might even work much better. Specially with limited amount of SW spots while still allowing people to swap; Guildwars with higher amount of points should get more badges/better prize. Maybe something like first A-C guild wars get X amount extra something and next D-F would get only Y amount of extra something and so on added to their prizes... This would motivate people to play in higher guild and win better enemies as wars with lower points would give crappier prizes. Probably lesser people together with point-droppers will whine then, but that's life and this is P2W game anyway. Can't get all the best without being the best. Might even motivate some e-peen dudes to gear harder to bring more incomes to GF...