Drafting Ravnica/Guildpact/Dissension

Heya folks. Any ideas on how to draft Ravnica/Guildpact/Dissension?
Normally, 6 of us buy a box and use 6 packs for prizes, and divide the
other 30 up so that we have 5 apiece. However, in this case, for the
first time, we've decided to draft the whole block. Although we all
loved the last two sets, we've been annoyed that there are essentially
only four and three decks that come out of Ravnica and Guildpact,
respectively.

The prob is that with 5 packs, there's no great way to represent the
stuff. Ravnica covers 4 guilds, so we should have more packs for that
than for Guildpact and Dissension, but it's tricky.

For 5 packs, I THINK we've kinda settled on 2 Ravnica, 1 Guildpact,
and 2 Dissension. The reasons are:

1. Ravnica covers 4 guilds and should thus have a larger share.
2. Guildpact and Dissension covers 3 guilds and have a smaller share.
3. However, Dissension contains generally more multicolored-related
cards, AND is the set currently generating interest, so we're giving
the 5th pack to that.

The probs are of course underrepresentation or overrepresentation of
the guilds. It depends on what set you use as the measureing stick,
but using Ravnica in the above 2-1-2 scenario, Guildpact is
underrepresented, and Dissension is overrepresented.

Does anyone have any better ideas? I can't seem to find a "proper"
way to do this... I'm am not STUCK with the idea of 5 packs either.
A 4-3-3 ratio would be best obviously, but is cost and time
prohibitive.

Thanks,

RIck