I ultimately took the elder peer to its logical extreme, going with an older high schooler but hitting on the flirty, intimidating sort of personality that is usually thrown in on the trope that inspired the age up. Figured that would provide a sharp contrast to the deeply introverted Leonard.
Looks like we have another contributor on the P branch as well. I'll see how I can adjust to those revelations as well, as I go about responding to that and F as well.