Not sure how I feel about the MACOS becoming Starfleet Security (I'm still sticking with a 'Starfleet Marine Corps' idea - I've always viewed Security as exclusively shipbound security guards, not front line troops) but otherwise, it's great.
Well, we've always been shown the same security personnel handling groundside and shipside matters, so that's what I aimed toward. And I wanted to have some tie back to elements of ENT, and to keep Kimura around as part of the crew.
Also, is there a retroactive source for
the Defiant insignia as shown in "In a Mirror, Darkly"?
That's just the generic Starfleet emblem we saw throughout TOS -- it's seen on the "racing stripes" on the side of the
Enterprise's engineering hull and on the shuttlecraft, and you can usually see it on the wall behind admirals on the viewscreen. I'm not sure what significance it would have in the 23rd-century scheme, but my intent was to keep things loose enough to suggest that my scheme could just be the ancestral form of whatever Starfleet's organizational framework has evolved into by TOS. The distinct fleet insignias could still represent separate fleets in the TOS era -- the
Constellation coud've been administered by the Andorian Guard just as the
Enterprise is administered by UESPA -- or the structure could've evolved into something else that uses those logos for historical reasons, the same way the historic UESPA arrowhead (whose chronologically earliest appearance is on the
Friendship 1 probe) comes to be adopted by Starfleet as a whole by the TMP era.

Christopher I like the new uniform designs how did you come up with the ideas for the different designs for uniform patches and signias for the different Starfleet uniforms?
The mission patches on the sleeves are following the precedent of ENT. I didn't design any specfic ones, and the Starfleet Command patch I described is the one seen in ENT. As for the insignias representing the fleets, I've felt for a long time that that was more likely than having a different one for each individual ship, since we saw a lot of non-
Enterprise personnel wearing the arrowhead in "Court-martial." And we now know, thanks to its appearance on the
Friendship 1 probe and on the enlisted rating emblems in ENT, that it was a UESPA insignia as far back as the 2060s. Given that Kirk said in the first season that the E was administered by UESPA, it seemed reasonable to assume the arrowhead represented the "UESPA fleet" and that the other ship insignias we saw represented other administrative divisions within Starfleet. As I said above, the European Space Agency provided the model for how early Starfleet could've been organized.
If you're asking how I chose the specific patches: well, the IDIC for Vulcan was obvious. The
Antares emblem from "Charlie X" was a good match for Tellar because of its hooflike shape and because I chose them to handle supply and shipping, which would cover freighters. The
Constellation "pretzel" looked vaguely like it could be
Andorian script, and I figured maybe Decker's ship could've been assigned more to defense than exploration, given his rather aggressive attitude. And the
Exeter insignia was the only canonical TOS-era one left, so it went to Alpha Centauri.
It's going to be interesting to see how the fleets, themselves, are integrated. As McCoy observed in Ex Machina, most ships were done by their owner's races. It makes sense when we assume the Federation Starfleet is going to be a bunch of pre-existing Starfleets shoved together.
Initially, yes, but the book does explain why later Starfleet vessels all seem to conform to Earth design sensibilities.