I see the confusion - but not - that's not my suggested strategy. The reason booking a Tier 1 later in the day as a pre-book is because it allows you to exchange a Tier 2 - as your first FP for another Tier 1 - this would be particularly important if the Tier 2's aren't necessary or throw aways.So we are assuming that 1) Tiers don't matter the day of and 2) everytime you use an LL you can book a new one (even the second one and the third one)
First off, if we believe the above to be true, then tier 1 and tier 2 LLs all become equivalent when the day starts, it doesn't really matter which is which. 8 AM Tier 2, 9 AM Tier 2, 3 PM Tier 1 vs 8 AM Tier 1, 9 AM Tier 2, 3 PM Tier 2 are both equivalent states, so booking a Tier 1 in the afternoon vs a tier 2 in the afternoon with your strategy doesn't make a difference.
Your proposal is to do the following
8 AM - Haunted Mansion
9 AM - Pirates
5 PM - Big Thunder
Then enter the park and go on Haunted Mansion, then have the following:
9 AM - Pirates
5 PM - BIg Thunder
6 PM - Space Mountain
And then at that point do Pirates 9 AM, Small World 9:20 AM, Dumbo 9:40 AM, Teacups 10 AM like that? All while holding a 5 PM Big Thunder and 6 PM Space?
I guess if you are certain you can accomplish that it would work, but I don't think that's what I would try to do. It seems like a lot would have to go right to make it run smoothly
8am Haunted Mansion
9am Pirates
3pm Tiana's
Go in ride Haunted, then book the next FP as soon as you can as close as you can to your last one
9am Pirates,
2pm Space Mountain
3pm Tiana's
Then you ride your 9am.
Then you have a single FP you can cycle trying to get Big Thunder and Jungle, peter pan - IMMEDIATELY if you like. And you'll also have 2 already pocketed. So at 9am you might be booking your Big thunder for 9:15am. Then at 9:15 am you might be booking your Jungle cruise for 10am, then at 10am you might be booking your Peter pan for 10:30am.
If you book your Tier 1 first ... you end up
8am Tiana's (though no one would ride this first thing I think)
9am Haunted
10am Pirates
You ride Tiana's then go and book Space at 2pm,
9am Haunted
10am Pirates
Your ride your 9am - but now you can't book anything until 11am ... so you try to book another Tier 1 at 11am or you can book it at 3pm or 1pm. At this point - all things are equal - but in the first plan you are already able to start cycling through the Tier 1s as fast as you can. In this second approach you now have to wait until after 10am to book another tier. At 10am in the first approach you could be booking your 5th tier 1 - the second approach you'd be booking your 3rd.
Now - ALL of this is subject to availability, but if my experience with Genie+ and Fastpass+ is any indication - the first approach is quite possible.
Another big question is whether you can modify - because if you can enter the park and then immediately modify your pre-booked FPs - well - that completely changes the equation.