Not to come and rain on he parade, I would love this, but unfortunately due to the way Wolves' Den matches people, you could only match registered teams of a similar combined rank. This is a problem because it will limit your number of matches unless there is a huge amount of interest.

If you get enough interest, I suppose you could do a prize for teams in a rank range i.e. teams ranked 0-10, 10-20 etc.
Although you may end up getting one person rank 45, for example, teaming up with ranks 1 and 2 to bring the overall average down and get into the lower tiers while having all the skills.

I still think SE should allow custom matches. Set ilvl caps, turn morale on or off, enable PvP skills, damage modifiers, party restrictions (eg the 1 melee and 1 ranged setup), toggling the current job restrictions (such as Cleric Stance and SMN raise).