(Another) Question about 'too small' penalty

[cwburnett]

In GW3, I've possibly made the mistake of using 757s for my longer range/higher capacity routes.  In reading the forum, I see a lot of people talk about the 'too small' penalty coming in later after a fleet selection has already been made and I may have mistakenly set myself up for that as well.  I'm specifically looking at my TATL routes, which I use the 757-200 on now and have no warning and have reasonable yields, and most airports won't support anything larger than a 752.  However, I'm concerned from reading that in a few years, these planes will become useless.

So - my question:
I am considering buying the 757-300, which can just make the route and increases my capacity to > what a 767-200 would carry F9 C25 Y174 for a total of 208 pax (and about the same as what a 767-300 can carry).  If I switch to this aircraft on this route, thus not adding another fleet, will it increase my 'too small' range to what a 763 would be, or will I be penalized sooner because even though it carries more pax than a 762 (and ~ the same as a 763), the system averages the seating capacity of the entire 757 and entire 767 family?

Basically wondering if I'm considering these four aircraft for ORD-LHR, will I be unduly penalized for choosing the 757-300 over the 767, or will the system choose 763>753>752>762?
767-200 with 184 seats (F8C24Y152)
767-300 with 216 seats (F8C24Y184)
757-300 with 208 seats (F9C25Y174)
757-200 with 189 seats (C15Y174)

I can't find a straight answer to this question...anyone have experience with this?  Before I become the launch customer for the 753...

[schro]

Too small warning is based on the seat count of an entire fleet in aggregate and not the individual model. Average seat count goes up for the 757 with the launch of the 300.

Too small warning is based on a Sami random mix of seat count, distance of route flown, demand and domestic vs international flight.