I'm having lots of luck with a new strategy that I call the "Party" strategy.  and it's also a good way to keep my units organized and updated with the newest equipment. 

Basically I create "Parties" of units that I keep together fairly strictly rather than just organically moving units around.  Each party consists of the following:

1) A caster 3-4 MP
2)  A custom designed scout unit with a Club, Shoes, and the Scout pack (The one that gives visibility)  3MP
3)  One Or More "Army" units consisting of either: 
     A)Most armored custom unit possible
     B)Sand Golem
     C)A low Intelligence Champion Loaded with Armor and Weapons
     D)Familiar or Guardians
4)  A pioneer

They all travel no more than 3-4 tiles apart with the Scout leading.  If they have no pioneer they don't go too far from the city.  If they do have a pioneer they can go wherever they want.  Every once in a while they head back to the city to pick up equipment and heal.  The scout draws enemies near (keeping in mind their max MP) and then the entire party stacks together to fight, including the pioneer.

My First major upgrade to the party is to get everyone to 3MP if I can, including the pioneers.  That means sending all 2MP custom units back to the garrison, exchanging them for ones with with shoes, casting Movement on the sand golemn, and dispelling the Familiars.  Eventually the pioneer gets shoes too.  Everyone who can't easily upgrade to 3MP Becomes garrisons, with the other useless champions.

If I have extra cash I hire all the champions I can.  If they will not be one of my chosen few champions, They will get shoes and move back and forth between the party and the nearest city, shuttling potions, shoes, armor, weapons, etc....  If they are around the party during combat they will join and stand in the back, alwasy upgrading their CHARISMA on level up for extra prestige when the go back and garrison the cities.

The pioneer is the cool thing.  Once the party gets inured and it's too far to walk back, just have the pioneer drop a city.  Heal your units, send a caravan back with your "messenger" and build a new pioneer.  Use the new city to buy and sell stuff.  Once the caravan has made a road,  and you have built a new pioneer for your party, you always have the option of disbanding the city.  In this way you can control the map quickly.

Eventually I promote a champion to a second caster and give him/her their own party, creating a second.  Making sure they are always replenished with scouts and pioneers immediately. 

I know it sounds kind of unoriginal, but always having a scout and pioneer handy makes the game much easier to play, and knowing that many champions will just be garrisons and messengers keeps the clutter down.  Also I don't really see the point of exploring too much further than I can send my party so I don't have a lot of scout spam.

Let me know if this idea helps anyone.