I think it's a fundamental conceptional problem, regardless of what kind of strategy game you're playing.
Land war and naval war are fundamentally different in real life. Most of the time, land war follows the pattern of "resources exist in enemy land -> we send our guys there -> we kill the enemy guys there -> now it's our land -> our resources."
In contrast, most naval wars are not fought for resources, but for access and denying access to the enemy, which in turn greatly affects land war - Mahanian doctrine and all that jazz. Very different "mechanics" in real life. It's fundamentally different, therefore it translates into games fundamentally differently. And, well, game developers have limited energy, money, time and knowledge, and they'll sacrifice a deep, convincing naval war experience in favour of a (hopefully, lol) deep and convincing land war experience.
I agree, the difference between ground and see combat is pretty extreme:
Land and naval warfare operate at very different scales, both logistically, and strategically.
That is, you cannot really "establish control" at sea as firmly as you'd do on land, let alone having frontline, but on the other hand, you can also "soft control" a much larger area.
The issue is that very few games can afford to have totally different mechanisms for both.
World in Flames and World at War: a world divided both managed to have a very differently feel for land and sea battles:
As you can see in WiF, land has a ton of hexagons, but in sea, you just stack ships in one of the sea area and that's it. So a single fleet can control one third of the Mediterranean, while an army corp will control a single hexagon and its direct neighbours. The numbered squares are for "ship speed/scouting". The higher the better(slow ships are limited to lower tiles, as are ships that had to move from another port, or remained at sea for an, extensive period of time), but if you split your fleet, and the opponent manages to get surprise on you, he can decide to engage only one box at a time.
However, enemy naval units can coexist in the same seabox, and fail to find each other (or one can succeed in its search check, while the other might fail, which will usually happen when a fleet with carrier/land based air support fights one without it).
World at War is much less extreme in that land units control much larger areas, but Sea units can move a lot, and have limited detection capabilities so you need to guess where your opponent is (you commit all moves at once), while land units will never attack in the dark.
Some sea only games are also pretty cool(rule the waves, or even games like Port Royal/Patrician 3...), but it's a lot easier if you don't have a ground component, or a minimal one:
in OG Warplan Pacific (the one from 2014, I haven't tried the new one yet), you and your opponent both give order simultaneously, so you have a good chance to miss the opposing force, but you can guesstimate where it can go depending on where the fleet is based, and where it has land air support.
Ground combat is heavily abstracted, though.
In a way, it is the same with most space 4X: ground combat is very abstracted, while fleet combat is way more detailled.
These 3 games sadly have some issues:
- WiF is a board game first that takes 100h to play (and quite a few square meters), and the PC adaptation is still lackluster, without an AI...
- WaW: A world Divided is pretty good, but mostly in MP, and I am not sure there is still a community left given how old the game is.
- OG Warplan Pacific was pretty sluggish last time I tried it.