99% of mechanics know that timing tools are required, i have a tool box drawer full of labelled timing tools for vw engines, audi engines, merc engines, bmw engines so on so forth and all are genuine equipment. most other mechanics i know also have these tools, this is your bread and butter for your average tool cabinet. the only difference comes with those cowboys who think they can wing it with cheap copies of the timing tools and recon they've seen it all before, those are the ones who mess the timing up.
i always wondered where this obsession with 'specialists' comes from, but i'm certainly not out to try and change folks minds. if you want to pay over the market price for the same service that you could get for much cheaper then go ahead, at the end of the day it's all about trusting a workshop or mechanic to do the job correctly. if that's a specialist for you then that's fine
just don't believe the hype that a renault sport specialist is somehow more equipped than someone working on all marques of cars when it comes to non routine maintenance. if they're professional, they'll follow the workshop manuals and use the correct technical data. not much to go wrong there!