lvl 11 Paladin: Which units?

[Stardust]

First one that comes to my mind is Shaman, definitely and excellent unit in both range and close combat (totems rock!). You can get them in the Orc castle near where you first arrive at Freedom Isle however you have to beat a pretty tough army before you can recruit Shaman (they are heavily melee based so your current army might suffer some casualties).
If for some reason you don't like Shaman try Sea Dog or Devilfish, there should be plenty of supplies for them in the area. Sea Dogs are decent melee for their LDR and the ability to attack multiple units. Devilfish will need a bless from your Inquisitor and they will swallow anything blocking their path (and great initiative/speed too).

Good luck.