Sorry for my belated response about toddler play dates.
You are absolutely right: I've only needed one hosting toddler and one guest toddler to throw a toddler play date.
Only the Mansion Baron households have the party requirement, though, which is why I think that bloodline should not go first in a weekly rotation, just so they have the option of toddler play dates to meet their party requirements.
I also have two questions:
Q1: The Gen4 retail heir and I lost track of time fishing for his museum collection until 6 pm Saturday. It took "us" much longer than anticipated to place his museum items, make his 3rd friend, 2 enemies, age himself up, move spares out, then move the heir out and invite new household members to move in.
By the time "we" finished it all, it was 5 a.m. on Sunday of Week 8.
My question is: Has my Retail bloodline failed the challenge?
Q2: I got all caught up in frantically trying to get the Retail heir moved out, even though he wouldn't have time to try for baby.
In this case, should I have just finished his requirements, aged him up, then left this Retail household until the following week? (I'm thinking, yes...)