It, IMHO, comes down to what size unit you are trying to move.
If we go with 8 man squads, then it takes 2 Valkyries to move a platoon and the Hoplite is pretty useless.
With 6 man squads, then 4 Hoplites, 3 Legionaires, 2 Retaliators or one Valkyrie move a Platoon. (Though the Valk is short...