After 30+ years painting I would recommend a good Sable brush maker is largely irrelevant as if you are using acrylics you will kill them quite quickly & even brush cleaner will only extend this a bit, so spending £8 on a brush I would spend £3-4 on is a waste of cash. Fine nylon brushes also have there uses especially if you are using artists ink for lining etc but they wont take the abuse levels of say lots of dry brushing a sable or even a squirrel hair one will.
As an all rounder size I use size 0-2 mostly with a good point & a 5/0 for fine lining with ink and some detail on a 6mm figures. I use brushes which have lost the ability to hold a point for general dry brushing & applying white glue to bases.
Small area dry brushing I use my normal brushes & hope they recover. I have a couple of 3/0 nylon brushes I use for artists inks. as well as a selection of size 6+ squirrel hair brushes I use for priming, & varnishing.