Does Phys/Shield Warlord only come good late game?

It depends entirely on how you’re levelling it. 2-handed Forcewave or 2-handed Blade Arc should manage fine on the Soldier side or Vire’s Might on the Oathkeeper side for your standard strong levelling skills.

Melee Cadence is going to have issues, especially if it’s 1-handed. It naturally lacks good AoE when compared to skills like Forcewave/Blade Arc (as mentioned above) or Primal Strike as examples and relies on skill modifiers or gear/devotion procs or WPS with AoE to cover it in those area - things you’re not going to have for a significant amount of your levelling experience, thus Cadence is going to clear crowds slowly. Not ideal.

Retaliation is in a similar position to Cadence but mainly because it is reliant on gear to provide the bulk of it’s damage bonuses, especially end game gear. So again, a lot of your levelling experience is going to involve clearing or killing things slowly.