One thing I learned during my many years of 40K is that the Emperor Protects, and if you don't roll that 5+, you better have three more Guardsmen ready to take out whatever xeno monster you made them charge.
Difference in approach, I guess. I'll concede that I'd personally much rather be a soldier in your army than mine.
Most recent attempt at Golden Horde KHAAAAN achievement goes like this. I own Ryazan, Vladirmir, Suzdal, Yaroslavl, Moscow and all of Tver's starting provinces. In order to do that I needed to have mil tech 4 before them. I attack Muscovy again. I have 30k men, half cav. I have 3.93 morale to their 3.67, 107 discipline to their 100, and all battles have been exclusively on steppe terrain. we have the same tech and I had one more shock pip than them. I lost every battle when our numbers were near equal. Normally I try to pick off their armies but in this war the Muscovy AI accidentally kept its armies near each other preventing me from stacking wiping them in a 3-1 battle.
The best explanation is that each and every one of my shock rolls was trash. But hey, I got the occasional 7 in the fire phase. That's like 2 dead Russians and .01 morale right? This is why I like space marines. If my rolls suck, I can atleast control my retreat once I'm allowed to retreat with minimal losses. With this, 1/3 of my army is dead before I can retreat, repeat ad nauseum. And when the game decides to give me a 7 on the fifth roll of the battle I not only haven't already lost the battle, I can actually utilize that 7 to win the battle.
This is a major exaggeration. There are areas of the world where navies are pretty essential, for example Indonesia. Outside of that, controlling the sea is super useful even though it's not strictly necessary. Ships are many times faster, especially in the Mediterranean. There is a huge strategic and tactical cost to moving your armies long distances over land if you're in a region with useful sea access. Blockades don't do a ton economically but they do make a significant difference in sieges. Strait crossings are situational but very powerful when used.
Sure, there are some niche scenarios where a combat navies matter due to islands. Point being, naval superiority rarely is a major asset. Yes, if I'm the one on the offensive it can be an asset to move troops quicker, but that's about it. Blocking Gibraltar or the Dardanelles isn't all that useful anymore because it is almost assured that whomever you are fighting is going to be able to go around the black sea. I've literally seen Spain and France walk around the entire Mediterranean to attack me in North Africa when I tried to utilize my naval supremacy to steal some islands or it might have even been a trade war to steal some ducats. I've had naval superiority as Mali trying to defend my coasts and make some colonies, but that didn't stop France from marching 50k men through the Sahara. Now you might ask, was I blocking Gibraltar that time? No, because I shouldn't have to blockade Gibraltar to stop 50k 16th century Frenchmen from marching though Spain, across Gibraltar, over the Atlas mountains and through the Sahara desert. I've been playing on the Pontic Steppe lately. Guess what happens when you attack Genoa? If their in the Empire, half of Italy and Germany comes storming across the Hungary, Poland and Lithuanian onto the steppe. So much for my investment into galleys. If they aren't into the Empire, then its only half of Italy. If you are playing in the Baltics, controlling the straights around Sjaelland is pointless. The whole of Scandinavia will empty out from Finland. Even if you manage to block Aland. You want to push Ethiopia out of Arabia? Well, good luck because they're going to walk up the Red Sea coast on the Egyptian side, and down the Red Sea Coast on the Arabian side. Navies are largely a minor strategic asset for the purpose of siege racing, and the ducats put into maintaining heavy ships are better spent on armies because the entire enemy army is going to be marching to your country whether you've a fleet or not. Oh, and your reward for beating these adventurers is that they get to safely retreat back to their homes only to make the trek again.
There is a similar case to be made with forts. Unless you have a string of forts going between two pieces of impassible terrain, or have completely encircled your country in forts, the AI is going to go around those forts, even if it has to march from Germany, over the Dardanelle, and around the Caspian sea to do it.