I just entered Pharos Sirius for the first time today through DR. Both DPS were SMN, and the last boss was definitely a situation difficult to handle with two SMN, when the minions need to be killed asap. After about ten wipes we gave up, and I suspect that with two of us, it made the battle way more difficult than, say, with a BRD or a BLM.
Of course it's a question of balance, but honestly in certain situations, especially in four ppl dungeons, the dps both being summoners can be a real pain, and a clear disadvantage compared to other party settings. Considering that DR is used by most players if not all (and thus random pt), I think that party setting should not make so big a difference in front of a boss, or maybe dungeons like this one should not be in DR (I already regret unlocking it).
And if most dungeons are easy compared to Pharos, there are still many bosses spawing adds that need to be killed asap with burst damage preferably, and even if it's still easily doable with two SMN, it's really tedious.
