Well.... phalanx based factions have a slighter easier going in VH/VH, than non-phalanx factions. BUT, the relative difficulty non-phalax based factions have compared to phalanx based factions has to do with the starting position. For example, nearly all phalanx based factions have an easier time getting thier economy up. That is because those factions already have an economic infrastructure in place. While, on the other hand, most non-phalanx factions have to build up thier economic infrascture from scrath. Now, once you add this up to the fact that you take more casulaties in VH battles than in M battles, the AI $ bonuses, etc, it becomes more difficult to non-phalanx factions.
For example: As the KH, in a few turns you get your a + income, and don't get me started with Ptolemoi and Carthege. BUT when you play with the Aedui/Arverni, you have to kill the other faction ASAP, and then by 268BC the Romani start pushing north. All the while you have build up economy, and your MICs.

One thing I would also like to point out, in vh/vh battles in all comes down to cleverness on the part of the human player. The way you play in vh/m IS NOT the way you play in vh/vh.