I think the systems tend to sound more complicated on paper than they actually are.
What you described above is essentially the same system that Tony uses, you have just simplified the description. You're not filling a second Platy, but you'll be filling something... so the number of parts is equal.
I use something similar to Tony's setup as well.
His, mine, yours, and probably a handful of other similar arrangements are all fine systems for filtering water. The Sawyer is a nice little filter. The secret to getting fast flow (for those who haven't figured it out) is getting the thing primed; once wetted out, it flows quickly. Sucking from the clean side is a good way to prime it.