That said, the "on average" point covers such a huge range that it's hard to make generalisations. The gap between low rank and high rank creeps is huge - much greater than the gap between low rank and high rank freeps. A creep raid with red and blue badges in it is just cannon fodder. A creep raid of green and purple badges is formidable. The same is true of a freep raid, but the difference is much less.
Both sides are also dependent on class mix. High rank Warleaders (and to a lesser extent Defilers) make a huge difference to a creep raid. Good Minstrels and Captains make a huge difference to a freep raid.
Running solo the difference between high and low rank creeps is enormous and probably the biggest change since I was last in the Moors at level 75. Unranked and red-badge creeps are so weak it's just horrible. But green and purple badge creeps are very strong. As well as the difference in skills and audacity, there's also a brutal selection process for creeps - it takes such determination and effort to get past the R6/7 point at which you become viable, that I imagine a lot give up, making those who keep at it that bit more skillful and ruthless.
Anyway, just my meaningless musings on a quiet afternoon at work.
@ Erlo - yes, I write for a living