zombie characters advantage over plants

Overall I believe the balance is pretty decent. Not perfect but asymmetrical games tend to have that issue. Certain characters could use buffs (I'm looking at you Captain Squawk), and others may need slight nerfs but the situation is pretty good in GW2.

Now the just ended portal event may skew people's perception of things since a superspeed Imp is a major pain to hit without a lot of splash and a superspeed mech is no joke either, but the imps vs corn event saw imps get thrashed pretty easily, mechs just don't do well with so much firepower focused on their large forms. Cacti are snipers and hitting a tiny super fast target that can double jump is no mean feat with a precision weapon. Chompers can do well but imps can get away fairly easily if they see you coming. Most Peashooters have splash and the toxic version seemed best able to deal with the imp hordes here. Sunflowers have a large clip size and solid rater of fire but their low health made them less than ideal for the imp swarms.