Another option to limit the usefulness of naval grade weapons in a ground combat role outside of very careful FFC coordinated strikes would be by imposing a strict weight limit, but going by weight is a bit complicated as an option. The Airbus 380 has a maximum takeoff weight of 575 tons without the use of TN minerals, which is equal to 11.5 HS is Aurora. It might move through the air like a whale and as such not really viable as a weapons platform, but TN minerals and enough thrust would solve that problem right quick.
Then again, there are optimisation questions involved; in space a flying brick is a perfectly viable design because there's no, well, anything resistance really unless you engage in a spot of most likely undesired lithobraking followed immediately with a rapid unplanned disassembly event of the entire craft and crew. Trying a flying brick design can work in atmosphere, but it's got two problems. The first is that it requires a lot of thrust, which is solvable, the second is that it will have the flight profile of a flying brick, which is rather harder to resolve without inducing an unexpected lithobraking event followed by the rapid unplanned disassembly of the craft and crew even with a flight computer handling most of the load.
Building something a little more aerodynamically stable would require trade offs between the space viability of the craft and the atmospheric viability of the craft. Worse, there are distinctly different design requirements for how deep and fast you want to go (you really, really, don't want to go Aurora standard speeds even at the lowest engine levels in an Earthlike atmosphere). This could manifest as a mass penalty because of the fact that while air designs generally work perfectly well in space, the opposite is not necessarily true and as such designs will generally look to be stable in atmosphere first and let the computers handle space stability while the now unnecessary wings and steering surfaces occupy mass and volume that could've gone more efficiently in space to other components.
Still, Steve, if you are coding for 'ship on planet', that's perfectly transferable to ships loading/unloading any kind of cargo, including troop carriers. Huge landing ships just became a lot more viable, especially if you can get the loading times low enough.