Most Decks of the Same Color Scheme:
Golgari 7
Selesnya 6
Simic 5
Orzhov 4
Gold gets a complicated mention.  There's also 7 of them IF you include the 3 commanders decks that are WUBRG; but still 4 without

Unrepresented Named Schemes:
Jeskai 0 (old spellspam deck was far too mana intensive and my only attempt at this combo)
Abzan 0.5 (I have a deck I consider WBG and its even named as such from its initial incarnation, but it does technically have 2 red cards added in there now)
Sultai 0.5 (I do still have a playable Sultai deck, its just so bad its not even boxed, one of only two decks to survive the winnowing despite its need of serious upgrades)

Final Counts:
69 total viable decks
7 commander + 50 winning 60-cards + 10 weak Tribal 60-cards + 2 strong but flavorless 60-cards
+2 borderline 60-card decks still in one piece on the top of the deck building Toolkit

Next Phase:
Amping up strong decks with my uber-but-unused cards
Retooling weak Tribals with auxillary removal/control options to find a fun balance point

   The first thought was to cannibalize the Warriors deck, long sacrosanct just b/c of its win record, and see if the Warrior framework could work in Mardu colors.  Surprisingly not, there were too many white must-haves in the warrior tribe.  Both Mardu and Warriors had a human subtheme however, so the potential for crossover/emphasis was palpable.  Looking for humans brought me to the White Devotion deck.  OK so now I can easily cannibalize that one to keep the Human subtheme in both originals, and I can use the White Devotion to reinforce the Warrior subtheme with a better sense of identity.  Although I would finish the new White Warriors second, having these two as seed material made the final product easy to design.  all it lost was some of the bolster mechanics for some powerful devotion abilities.

   Still focused on Mardu however, it increasingly looked like the boros themed cards were the ones that needed booted.  Too much white if i was going to import the new cards i wanted to add, and 6 of those new ones were now anchors.  enter the rats.  I've never had enough rats for even a half a rat deck.  most the black deathtouch ones weren't appropriate over here.  A lot of the newer red ones however, were actually human creatures that created rat tokens.  that was kinda perfect both thematically and to improve swarming offense.  by this point my average CCM was way higher than the original, so extra lands rounded it out. 

And so 3.3 decks have condensed into 2, both of which I think to be significantly better in quality and theme.  imaginative combos ftw