If you use SCH come as SCH/RDM. If you're relying on WHM, it's probably best to just make due without Phalanx. Worst case, you'll have to reduce the number of mobs you're pulling. The puller can make up for this to some extent by coming /WAR and keeping Defender up all the time. And if push really comes to shove, the RUN or PLD can cast Phalanx on at least the puller who will need it the most. Oddly enough, we've had a RDM in every party we've done so far. . . sometimes two. And a SCH to boot.
You could also come /RDM and only Phalanx the puller and any player likely to get hate and forego the Windstorm. . . although the damage increase from Windstorm is nice.
Here is a guide I put together on doing this method. Although, I did not address Phalanx when using a WHM. Fail:
https://youtu.be/PVFaXcud5ig