Never mind, I wasn't abstracting far enough. I was thinking blocks:pseudoshares, not blocks:shares:pseudoshares. So minerd won't know, but what's the difficulty difference between pseudoshares and shares so I can estimate?

I guess the difficulty difference between blocks and shares is bigger for the ltcoin pool, meaning I got 4 much smaller shares last night. Presumably after your estimate of 10 hours, give or take (a lot), I'll get one share from P2Pool that's a good deal bigger than the ones I got last night from ltcoin, right?