I like what you have been doing so far (in fact, you have been a reason for my BJ order). But assuming a steady network HR... Who are you and what did you do to cypherdoc?
Anyway, a 100 BJ are mining solo should indeed get more BTC than 100 BJ mining for a pool. However, most people have just 1 BJ and after taking a gamble on BTC in general and HF specifically don't also want to gamble on the roulette table know as block finding. People like me who rather have 12.25 BTC than 50% chance of 25 BTC.
clearly i specifically stated "steady" network HR to make it unquestionable that the expected yield from pooled vs solo mining would be the same given an equal orphan rate and no fees from pools. in a rising HR environment, which is what we have now, it's not as clear. still, given this environment, my personal experience soloing has worked better for me than pooling.
You're right, I totally read your post wrong.
But to answer your original question: Yes even with a steady network HR, the reduced variance of pooled mining can yield more BTC than solo mining for a long while. I have too little knowledge about probabilities, but I wouldn't be surprised if there's a greater than 10% chance pooled mining will yield more than solo mining over a year with a single BJ.
In your case you ordered 8 BJ's (right?) so you are closer to having a private 'pool' than most of us. I can't explain your current ownage of pools though. My best bet would be luck, but I don't know how much latency and downtime will affect the results.
And in the end using a pool also gives ease of mind and stability. Both which can be valued higher than more profit. After all T-Bonds still get bought, even though they have a negative inflation adjusted return.