Hey, let's have a Flare Forum party at the TrekBBS!
Timo: You're forgetting that the Aries already had a first officer of the Commander rank: Cmdr. Flaherty. So unless they were going to be co-captains, I'd guess that Riker would get that fourth pip.
Reverend: Believe me, nothing would make me happier than to see new, original designs for the conjectural classes (kinda like what you did for the Antares). However, I based my conjectural designs on several factors, of which the registries were only one.
1. The curious lack of more than one or two Antares, Hokule'a and Wambundu class ships in operation, going along with the curious lack of Ambassador class ships, as opposed to other vessel classes, at about the same time.
2. Between the mid 23rd century and the mid 24th, most major vessel classes had variants of the "classic" design for their era. For example:
a. TOS Connie = Hermes/Saladin, Ptolemy, Federation (and yes, I consider the FJ designs canon).
b. TMP Connie = Miranda, Constellation, Connie DS9 kitbash
c. Excelsior = Centaur DS9 kitbash, Curry/Raging Queen DS9 kitbash, 3-nacelled DS9 kitbash.
d. Ambassador = ?
e. Galaxy = too numerous to mention.
The Ambassador is the only major class with no known variants, but with four conjectural classes built around the same time. Hence, using Occam's Razor, I guessed that they were the Ambassador's variants.
Also, I'm still of the opinion that the Centaur design would not be right for the Renaissance class if only because it would make more sense as a new design rather than an Excelsior kitbash. I do agree with what you said on Flare that Andrew Probert's original Ent-C design (or more specifically, your take on it) would fit better as the Renaissance class. But I'm glad we agree on the Apollo!