So while I enjoy tanky top laners and junglers a lot, I completely agree and understand that fighters and juggernauts need to be able to tear through tanks. Utility tanks by nature thrive in team fights, so our AD and AP fighter/bruiser champs need a way to get a lead and win 1v1 in lane, and also an option besides full on team fighting. Conqueror gives them that tool to basically guarantee that after they complete like a full item, if the tank hasn't knocked them around much in lane, they pretty much own that sidelane permanently. I will say Conq could use some tweaking, but in general it, or something like it, needs to be in the game.
The Problem: Tanks are very one dimensional champs in terms of purpose, and are not correspondingly strong at that one thing (team fighting), at least not enough to make up for the fact that they have fewer options than other characters. Their power curve is not smooth at all compared to literally any other class and their item combinations are not efficient. To explain, they have a very small front end window to go toe to toe with fighters early game, and then at like 1 item fighters win the match up. The problem with that is that the tank doesn't have any other options at that 1 item powerspike besides sit in lane an hope for a gank. Unless the opposing team is stacking 1 damage type, they really don't want to team fight until they have like 2 items and tier 2 boots. That's the only way they have enough hp/resistance to actually be a legitimate vanguard. FH being the only armor item with CDR is a huge problem in a game with so much true damage. The tank items just don't work well together, as the most desirable and efficient combinations of passives /uses/stats don't exist in a viable manner.
My solutions: Quick and easy things to implement without having to do an entire rework of all tank items. These are not geared towards making the power curve into mid game a bit smoother, not at making tanks better in lane or scale super hard later. We've already established that their weak early game and susceptibility to getting outscaled by full damage in the late game is balanced. We just need to solidify/widen that window of power a bit.
1. Increase hp values of utility tank items slightly. Many tank items have between 350-400 hp, while items like Black Cleaver and Steraks have 400-450. So just bump those up to match. Push Adaptive up to 400, push Randuins up to 450, etc.
2. Allow Adaptive helm and Spirit Visage to retain Spectre's Cowl passive even when completed. This extra regen could be helpful in the mid game as we start looking into smaller fights or skirmishes, but allow tanks to stay on the map or recover for the next fight. Kind of that poor man's Warmog's passive until the true Warmog's kicks in.
3. Reduce gold costs for stacking passives. So if I build Adaptive and Spirit Visage, or Frozen Heart/Thornmail/Randuins...the combine cost of the completed item should be slightly reduced. Not by a ton, i'd say generally half the amount of the redundant item is fair. So like 375 (half of Spectre's cowl) or 500 (half of warden's mail) discount on the second item you build with that component. Yeah the item stacking is still inefficient, but you might be tempted to combine the passives that still actually work if the costs is reduced.
4. Swap out the Giant's belt from Firecape, and put in a Kindlegem in, also increase the combine cost by 200 so overall cost is static. This way Firecape isn't useless after lane phase breaks down, but still not insanely efficient like the Frozen Heart-Spirit Visage rush days.