In my opinion, this is the ranking of professions (with a brief description) of small-group (~3-10) combat in WvW:
1. Warrior – control, mobility, damage, everything but sustain (hammer being the most effective weapon of choice with either S/X or GS on swap to disengage from the thick of a fight/GS for amazing down-cleave)
2. Necromancer – great AoE damage/pressure if allowed, decent utility, bad mobility and priority target (Power works also with slightly less AoE damage and more single-target)
3. Mesmer – AoE burst/DPS, decent single-target DPS, stealth, combat mobility/slippery, not too much group utility, contribution to DPS is very player/skill dependent (PU builds are garbage outside of 1v1)
4. Guardian – great support through mainly stability and heals, highest sustain and damage mitigation if focused when played properly, decent control, low mobility with most weapons or builds, great at stomping/reviving
5. Engineer – lots of damage mitigation if played properly, tons of utility, mediocre to great damage depending on the player and build/spec, essentially a wild card
6/7. Elementalist – high burst with S/D (hardly any damage mitigation compared to other burst roles), lower damage with other weapon sets, decent mobility/control and awesome sustain with D/D (if not completely trained/focused), staff being too slow/not suited for smaller fights although slippery, other classes bring the same utility with more to offer
6/7. (Power) Thief – great single-target DPS (main utility – something else other classes can do more effectively in most situations), occasional high AoE DPS, hardly any utility outside of stomping downed players/reviving allies but with more risk than Guardian, (Condition Thieves are garbage)
8. Ranger – high damage with longbow, nothing but annoying with anything else, low survivability, hardly any utility outside of Binding Roots (Rangers are essentially the same thing as an up-leveled character)
Of the three classes you mentioned, Necromancer would most likely be the easiest to pick up, Mesmer for a slightly higher learning curve assuming you’re playing a burst shatter build, and I wouldn’t bother with Elementalist honestly (although personally feel it’s probably the most fun class).
