I believe you underestimate some people, there's definitely people that notice these things. It's way easier to see what kind of top sheet there is on a rubber, if it says TO5 and is very tacky; something is definitely wrong. I don't see why players would take the risk of "swapping" rubbers, and they don't really win on it due to the fact that it's against the rules
Thus I noted in the original post, that they don't seem to put a lot of effort into having convincing fakes.
If they cared, FZD could pretend to have at least a carbon blade from Stiga, rather than an Infinity VPS, which anyone paying attention would quickly realise he's clearly not using. The actual branding on their equipment seems to be a mere handwave targeted towards the undiscerning observer (which are probably the overwhelming majority of the market over actual EJs).
The convention seems to be, you need to do enough that you appear to be using equipment from your sponsors (at least for a high profile player like FZD), that only has to stand up to the most cursory inspection. Neither their sponsors, nor the manufacturers of the equipment they actually use seem to make much of a fuss about this very casual attitude towards branding to meet sponsorship requirements.