The only element in ZZZ I have three of is Physical, Corin, Billy, and Piper, and honestly a triple-physical team in Hollow Zero with resoniums stacked towards anomaly buildup, damage increases for attacks, and boosted assault really rips through most everything.
The three resonium classes I like best for that are Onslaught, Duel, and Shield. Energy isn't bad either, but I feel like I use my EX attacks less with the physical team than with the Electric, Ice, or Fire teams (all of which have Nicole as Support). They're not irrelevant, but basic attacks, counters, and chain attacks do the bulk of it. In that regard, Assist resoniums would probably rank above Energy. Having enough energy for EX attacks while a boss is stunned is typically good enough.
Actually, I suppose Onslaught, and Critical synergise pretty well too, especially since Corin and Billy both focus on rapidly inflicting hits, meaning more chances for critical hits.