here's the relevant fluff tro tro 3067
The Hauberk assault battle armor has its genesis in
Clan Goliath Scorpion’s aquatic Undine battle armor design.
With the Word of Blake attacking on all fronts, the
Great Houses desperately sought any and all means of increasing
their military output in the hopes of stemming
the tide. As Clan Diamond Shark had already established a
reputation for being willing to sell Clan technology directly
to the Inner Sphere—as was the case with their Mad Cat
II—the Houses discreetly courted the Diamond Sharks in
the hopes they would funnel additional Clan war material
their way.
In the case of the Undine, the Federated Suns made
significant concessions in trade for several suits of battle
armor. Hopes that this new suit could be deployed in the
field quickly were dashed—the Undine’s specialized nature
proved to be tactically limiting. Maintenance problems
(and the high price the Diamond Sharks were asking for
HarJel) also conspired to derail Davion plans. However, it
was felt that the basic chassis, which was more refined than
anything the Inner Sphere had been able to produce to
date, could provide a solid foundation on which to develop
a new assault battle armor that was capable of challenging
designs such as the Kanazuchi and Golem. With intense
fighting raging on New Avalon, and the destruction of
other key manufacturing centers by Word of Blake and the
Capellan Confederation forces, the AFFS turned to General
Motors on Salem to develop and build the new battle
armor. Armed with data spirited out of the NAIS before it
was destroyed, GM had the first prototypes in the field by 3069, and by 3070 the suit was in full-scale production.
the fluff in combat equipment makes it clear that the design existed before the purchase of the suitd and where entirely a theoretical exercise until the AFFS secured the undine suits,
so yeah the clans had nothing to do with the actual design process.
there's no evidance of direct sea fox involvement in the development of ANY inner Sphere battle armor (including, amusingly eneugh, the sea fox BA)