Not that it matters, what with the impending edition change, but Rage in 5th does not require the unit to charge. They have to move at top speed towards the closest visible enemy unit, if they run, they must run at top speed towards the closest visible enemy unit, and they must consolidate at top speed towards the closest visible enemy unit. They don't have to assault at all, and if they do, they don't have to assault the closest enemy unit.