I am sure the variances between two mods has something to do with how range/speed/power/batteries etc all interact.
In TMO, I have noticed small differences in battery charges times, especially between the S boats, Narwhal, and fleet boats. The older fleet boats like Salmon, Sargo and more modern ones such as Gato, I have noticed no difference. One thing Ducimus instituted as a fix for battery recharge times, which were excessive in all models, was the "Battery Fix" special ability, which is standard for all subs default crews. This crew member
I have no plans to adjust speeds, ranges, etc in TMO as they are close to perfect as can get, submerged and surfaced. I did some brief testing back when was developing mod, just to confirm some things, but I am quite happy with how Ducimus worked things out. I recall when he was working on this for one of the versions, amount of work, testing, tweaking, something I glad he did because not something I would have wanted to do lol. I would have if needed, but glad do not. . Surfaced rangesl, takes into account the ballast tank modifications used during war to give extra fuel. Given that along with battery limitations etc work fine and is historically accurate (within limitations of the sim of course), will leave it as it, spend efforts on other aspects of mod.