Even strength 1 is op and we still do 130% more damage as opposed to a quarter of a heart extra like in 1.5. I really don't think that leaving any form of strength in would be a good idea unless we put a cap on enchantments on swords :/. Eliminating strength and keeping it at prot 4 sharp 5 would be really dull I think as well. I really only suggested protection 3 sharpness 2 because it would be easy to set as the limit with enchantism and then editing the config of the thing they limit potions with not to allow brewing with blaze powder or ghast tears. If people don't like that there are more balanced styles of pvp out there :P
There's one I've seen on another pvp server in 1.6 that balanced it pretty nicely and it's pretty close to vanilla: prot IV diamond, sharpness 4 on sword, no strength 2 pots allowed (but strength 1 is). Everything else is allowed. A lot of players on survival go on that server to practice pvp, there's probably at least some that have tried it out. It's pretty much what buchan wanted but with sharpness 4 on the swords, you die too quickly with sharpness 5.
EDIT: I have no idea how to forum and I can't format. Also I typed this mostly on my phone and I think I screwed up the font size. Sorry about that lol
Also I think that Prot III sharp II is still better because it's more about inventory management. With legacy you can get 1 lucky combo and win. Sharpness is a really weird enchantment and it makes you do a random amount of damage, then that random damage is multiplied by 130% with strength. It's less about skill imo and more about luck - the lower the sharpness level the better imo.