The Tank Fiora Dilemma

When we talk about the problem here (which is not stand alone, see: Tank Ekko in the past), I feel like we're seeing a more fundamental problem than simply a balance issue. The problem with Fiora-Types is that they can fulfill their damage needs with 1-2 items. This leads to them being able to devote the rest of their item slots to beefcake because they've hit the bar of Enough damage versus something like an ADC.

However, if they can't deal this amount of damage with 1-2 items, they're not functional enough to fill in their required position. The question thus becomes, what is there to be done with this class of champion?