For WvW, what professions and builds can be played in both a zerg and solo roaming?

Is there a build that can do a bit of both, hold its ground in a 1v1, 1vX fight and also somehow tag lots of enemies in a zerg? So that you can roam when you like and join pugs and get lots of bags if you like as well. Something versatile.

Eh? All of them technically speaking.

In terms of builds the only relevant thing here is how much you have to change on a profession. Looking at only the 4 zerg metas, the guard and the engie will be furthest from the solo roamer. You need to swap out entire gear and skillsets. The necro is something in between since it may require a full rebuild if you run condi, or it may work just changing some things if you run a power roamer. The rev will be the simplest since most only need to swap weapons and skills (very few run condi).

But then of course you had to bring in "tag lots of enemies" into the mix. That eliminate one of them right away, the engie.

And then we have to consider your particular "1vX" requirement. That eliminate the necro and the rev because neither is particularly good solo outmanned if the enemies arent complete dolts, one because its easily kited and the other because it runs pretty glassy to be effective. That only leaves the guard... which isnt really that good outmanned either unless you dh trap instakill previously mentioned dolts.

You could of course expand it to non-meta professions, but then I refer to the first point - all of them, technically speaking.

If you are looking for the one unchanged build that comes the closest to being accepted in the current zerg meta and being a good 1v1/1vX... it doesnt exist. The 4 meta professions set the baseline, have to look elsewhere. Spellbreaker would probably fit - but its not meta. Soulbeasts would probably too - but zergs will laugh at you. Staff daredevil comes close... but zergs still wont have you. Decent weaver perhaps? Very few roamers worth their salt on power dps. The chrono could do it I guess... but you're only allowed to veilbot in a zerg and the average roamer build wont survive long. Plus the loot thing.

I would recommend Staff + shortbow Daredevil.

Vault and Bounding dodge combo for Zerg fights or tag them from range spamming shortbow poison field. Lots of bags.

Does well for roaming too. 1 v 1 and 1 v X.