This discussion arose from a disatisfaction with the existing Galactic Navy OXP. Not that it's a bad OXP...it is well made and is very popular. The problem is that it doesn't sit comfortably in the Ooniverse as we see it. We aspire to something different which does fit in.
Before we go too far, I think we should look at what we have already and what we 'know'.
1)From canon (Elite and Oolite) we know there is an HIMSN. Two of the native missions involve them. In-game we meet repreentatives, but have no direct involvement in any naval conflicts and never see any of their hardware. The Navy's title, and the personnel we met suggest an organisation reminiscent of Victorian England.
2) The Elite manual mentions a 'Galactic Navy' and suggests that most of the major battles are fought in inter-galactic space.
3) The only Thargoids we meet (in the core game) are the Warships and Thargons, sometimes in normal space and often in witchspace after a misjump.
Oofic and OXPs have expanded upon this, and therefore one of our first tasks is to decide what we want to adopt from these additional sources and what we wish to ignore. In deciding what to ignore we must consider that much of this is as real to many players as the actual canon and 'facts'.
For example some quite popular OXPs add many more Thargoid vessels, including Capital ships such as Thargoid cruisers and carriers. Are these going to be 'acceptable' in any HIMSN OXP? In 'Kaxgar', El Viejo offers a rather nice if quaint and quirky 'history' for the formation of HIMSN. Are we going to adopt this as part of the back-story. In my own Xeptatl's Sword OXP, there are new Thargoid vessels, and also (as far as I know) the only OXP involvement so far of HIMSN. The OXP revives a character from one of the native missions and features the heavy cruiser Thunder Child. Are these elements going to be woven into our back story.
Considering these points, where does that point us?
Let us asume that most or all of the above aspects are taken into account within a new HIMSN OXP. All this taken together suggests that we are right in considering adapted 'core' ships for the HIMSN fleet. While the navy does have a capital ship (Thunder class cruiser - OXP) and is known to be conducting R and D on new ships (Constrictor - native mission) it is nonetheless a relatively small organisation working with limited funds. The exact relationship between GalCop and HIMSN is not clear and there is no suggestion that GalCop is funding the Navy, so I have to assume that the sytems that have co-opted into the Navy are the ones funding it.
It will be a relatively small organisation, probably inadequately funded, and stretched to the limit trying to control the Thargoid threat.
The main 'battlefield' would seem to be inter-galactic space, and to a lesser extent inter-stellar space. Both are easy enough to get to. Therefore the Navy will have little trouble mobilising forces where they are needed. As even non-jump-capable ships like Sidewinders can hitch a lift, getting a large force into intergalactic/interstellar space is relatively quick and easy.
To my mind this makes large vulnerable ships like carriers a bit pointless. They would serve no practical purpose and would be so vulnerable that they would have to stay well clear of the battlezone ...we would most probably not see them anyway.
Is this OXP even going to include battlezone elements. In some ways I would prefer a continuation of the 'feel' of the native missions. Small special ops missions (although much more demanding ones than the native missions), and perhaps an occassional active combat mission to interstellar/intergalactic space but avoiding the mass shoot-em-ups that characterise the GN OXP.
The Elite manual says
and throughout the 8 galaxies there are at least 50 war zones between humanity and Thargoid
Perhaps we should agree on where a few of these are (maybe one per galaxy, maybe less than that even) where we can give the player a chance to get their hands dirty with the Navy in a larger 'set-piece' battle, but mostly I would favour smaller, but more thought-provoking and challenging missions.
And finally, back to the ships that will actually appear in the OXP.
Asps and Sidewinders based on their civilian counterparts as fighters. A 'Destroyer' possibly based on the Boa2 as a counter to the Thargoid Warships. Possibly a S&R vessel based on the Moray. And really that is all that is needed unless a capital ship is wanted for a particular reason. To my mind that would only be wanted if the player gets involved in a major battle and would expect to see a large 'Flagship' heading the fleet, and this role would not sensibly be filled by a carrier.