All you got there is the basic things ofc but think about the other things of the build it also depends on playstyle.
it's rlly effective actuly, you would just have to get the items acording to yhe enemy team comp and who is were and so also teh question is do you get ganked alot ? if you do then you doing it mostly right since you get em all top but it also depends if you get crushed to hell or you still can keep em away.
Health = more survival + if yiu meet like cho or darius they just nom other stats lvl 6 to stop em health is effective ofc i sometimes get magic resist part or armor b4 health depending on the enemy and their playstyle.
all you wanna do at start is get the farm you wont be that interested in getting too manny kills.
ofc you can snowboll like hell with this build.
mordekaiser is more of a spell pen champ and being able to sustain the enemy dmg.
warmongs early = capped fast.
if you meet a udyr jungler you would want to be extra careful cause he is one of the ebst champs vs morde with wit's end and madreds sincehe bear tiger turtle bear tiger bear tiger turtle bear on you all day.

true dmg weak vs health except vayne ofc.
thornmail or even randuins if you want but i prefer thornmail since ignite thornmail and ult vs a ad carry to get that clone and you can just walk fourth and back on towers.
throat if you look at this builds dmg output it ait as sucky as you think because you would allso maybe be wanting a tank as extra like mundo or sumthin.
clone = dmg clone doing dmg = shield warmong + force is alot of health regen + ive even gone double warmongs cause i would need the health when it works alot better than armor or magic resist.
and this aint just some build i made on the whim i've playd alot of morde.
he was the first champ i did rlly good as and i went onto dominating by using someone elses build and from then til today i've been focusing on 5v5 so here it is my build for 5v5

Tank-kaiser is extremely ineffective. Your passive synergizes with resists, not flat health. The more resists you have, the stronger your metal shield is. Also, I just don't see you doing any damage all game. If you build pure tank, your enemies will ignore you in teamfights and slaughter your carries.