Whilst I am sympathetic to the overall aim of this, things like this:

She would have expected people to name figures such as Quintus Lollius Urbicus, who became governor of Roman Britain

...do stand out as being a a bit unrealisitic. I mean, how many governors of Roman Britain of any race or nationality can the typical Briton actually name? I'd be surprised if it was more than 1 and probably less than that.

And if the expectation is that anyone would know of this guy only because his chief contribution to history is "being black" then I am not sure what we are gaining here.