Unsuprisingly, you are not talking about the left/right as it has been rendered in psychological terms, but in stereotypical renderings that fit you far left ideology. To start, I am centre left.
Be careful of screaming ‘fallacy’ unless you can’t speak in adaquete terms otherwise. The entire concept of ‘diversity’ (by non ideological means) describes a pool of people that are naturally different. ‘Equality’ describes a pool of people that are all the same. If anybody is an earnest proponent of diversity, regardless of which viewpoint/position they hold, then the a priori assumption is that people differ — and that sharing difference is important. Equality and diversity — in terms of sheer langauge — are diametrically opposed. If you hold that everybody is the same — ‘equal’ — then you can’t make any arguement for diversity.