#1: Will -- The most important stat of all. In general you want 7, 9, 15, 17, or 21 and a style that makes sense with the number you have. Lots of exceptions, but those values make a ton of sense.
#2: Strength -- Every warrior (except possibly AB's) needs Damage and/or Carry, and strength plays a huge role in both (and that without mentioning the ability to use weapons, endurance, attack skills, and parry skills). You need "enough" strength. 9-11 (unless you are small) is a good place for many styles. Bashers really need 11 or greater.
#3: Wit -- If you're talking about 17 or 21 wit, I could place wit higher in the priority, but below 17 wit, I pretty much only care about enough to use my weapons (11 is enough for almost every weapon, 13 is important for Lungers to use LO)
#4: Deftness -- Skills and Weapon selection. 11 is a HUGE break point for both. If you aren't an AB, more than 11 isn't usually very important. For AB's, Deftness may be the #1 priority (since they get bonus attack skills at creation for deftness).
#5: Constitution/Speed -- I put these equal and last in the stats you can add points to. Most managers don't add to speed except on pure offensives or on Lungers to get to 5 speed (superstitious about 3-4 speed lungers underperforming). Constitution is your primary source of hit points. Not all that useful to pure offensives (though being able to take a hit is not a bad thing), but more con is better for all other warriors. There aren't many warriors who expect to never get hit, more is better when you do get hit.
#7: Size -- You can't change it so really you just look at the rest of the numbers and see what makes sense. Size impacts damage, so you should consider your expected damage rating when designing a warrior. Little damage is crippling for 8 styles (Aimed Blows and Total Parries excepted). There are ways to deal with little damage, but you don't want it. High size (15+) penalizes you in defense and parry skills, so realize that when choosing a style that uses those skills on a big guy. (Recommend not going PL, PS, PR on big guys unless you are prepared for it.)
Hope that helps! -- Assur