Sounds like you should go with half a vial per jug, then.
I'm guessing you're using the same wort recipe for each, so I'm curious what type of hop schedule you're going to use in order to make the beer beer but not overwhelm the yeast subtleties with hops flavors. Actually, the whole recipe would be interesting, if you don't mind.
I have made this before and it turned out pretty good using safe ale 05. Craig's Travelin man, a morebeer kit.
for 10 gallons, 90 minute boil.
20 lbs 2 row
2 lbs honey malt
1 lb Crystal 15L
.5 lb Carastan
2 oz cascade, 75 minutes
1 oz Northern Brewer, 20 minutes
1 oz Cascade, 5 minutes
1 oz Northern Brewer, 1 minute
I can hit my gallon marks pretty well, over a 90 minute boil I will boil off three gallons, which will leave me 11 gallons and after post boil shrinkage I will have around 10.5 gallons. My plan is to do a ten gallon batch, then after chill down add oxygen directly to the wort in the boil kettle (I have a wielders tank filled with O2, Sanitary Filter, and .5 micron diffusion stone). I use hop bags and do not add hops free hand to the kettle. So I have very little trub to deal with post boil. I will split the wort into my ten 4 liter jugs, I will then pour in about half a vial of yeast into each jug, cork and airlock each. What I expect is that each of the ten jugs should have different flavor profiles. There is a home-brew club nearby that has a few members who are BJCP judges and I plan on seeing what they think of my beers. The yeasts should give each beer a different flavor, or at least that is my hope. This project will help me perfect this brew to my own tastes. The recipe is not overly hopy (it comes in at about 34 IBU's) and has a pretty good balance.
If this project turns out well I plan on using the remaining yeast on a stout also. I haven't decided which stout to make as of yet. My end goal is to have my Keezer filled with 6 different beers, Pale Ale, Stout, Honey flavored Pale Ale, Brown Ale, Alt, and Session.