Is WoL the only one able to master/handle all the classes at once?

[Elkanah]

Tataru Taru is both a Receptionist (spy), a failed miner and a failed Summoner (at least level 70) if you can call that taking on multiple jobs.

She was also a weaver too, if we count the tailored stuff she made for Yshtola and the WOL in two different portions of cutscenes.