Switching to Undead

I'm wondering if it's viable to switch to undead with the units I have right now. Currently I have T3 Druid/GR, priests, drummers and a fairy for support. My undead team will be a T2 Lich, T2 Dark Admiral, 2 Succubi, 2 support Liches, and Priests/Drummers. Is it worthwhile to switch now, or should I wait until I have 2 more Succubi? Downgrading to T2 from T3 isn't much of an issue since I don't have the economy to regularly break 1350 gold level yet.