Very interesting.

Tanks are fascinating to evaluate as an engineering challenge. They need massive amounts of heavy armor to be survivable, which requires more powerful engines and decreases range and speed.

Too slow, and your design won't survive long. Too little armor, and it won't either. Other than a limited engine snorkel, I'm not aware of any US tanks to employ this design currently.

That massive snorkel that accommodates people getting out through it (in what I'm assuming is a Chinese or Korean design based on the photo) seems like it would likely add weight and complexity. Tanks also obviously need room to store ammunition, which is very heavy and bulky for the main gun.

Military doctrine is usually (when feasible) to soften an enemy position with artillery and/or airstrikes, then move in with ground troops to secure it. Tanks are a blessing for otherwise soft and squishy infantry, which usually follow just behind and take advantage of the mobile cover. Upon contact, the tanks engage the enemy with a 20mm+ machine gun or their main gun, then the infantry mops up. Of course this is for larger, full scale engagements.

Now if you're in a geography with lots of relatively shallow lakes or rivers, seeing a couple of these monsters suddenly rise up out of there to pound your position before you can counter-attack would be a nightmare.

While AI is advancing by leaps and bounds, I'll bet good money that kill authority will not be granted to anything not directly controlled or ordered by a human for at least 20+ years, if ever. At least not by actual nations. Insurgencies / terrorists will use anything expedient.