I'm trying to parse out mounted combat as a ranger with a ranger's companion.
From Controlling a Mount (PHB pg. 198):
You can control a mount only if it has been trained to accept a rider. ... It moves as you direct it and it only has three action options: Dash, Disengage, and Dodge
From Ranger's Companion (PHB pg. 93):
The beast obeys your commands as best as it can. On your turn, you can verbally command the beast where to move (no action required by you). You can use your action to verbally command it to take the Attack, Dash, Disengage, Dodge, or Help action.
Assuming a ranger's companion has been trained to accept a rider, what's the action cost to the ranger of commanding it to Dash, Disengage, or Dodge? I assume it would be free while mounted and cost one action when not mounted.