Phalanx units as in 4.5-7.5 metres of spear obstracles, more shields than you can count, and decent armour?

Yes: they will probably be somewhat more resilient in RTW than they were in real life; then again many missile units don't seem to suffer quite as much from realistic real life conditions either. If you try to soften a phalanx up from the front, you must use at least javelins or *many* archers/slingers: don't expect miracles though. After all you are playing according to the rules the phalanx unit likes best, attacking it head on.