Regarding Paladin, Embolden is aligned with Trick, which falls squarely in the FoF window, not the Req window. Embolden may have no healer and caster synergy, but with DRK for example, there's still a massive chunk of their burst window that's physical (C&S, 2x Plunge, 5x Bloodspiller) and does benefit from Embolden. Devotion may be an omnibuff, but its far longer cooldown naturally drifts from other major buffs like Chain Stratagem, Dragon Sight, and Technical Step, while Embolden remains squarely in-line with them for the entire fight.