Smaller brushes for gouache

I need smaller flat brushes so I can do some smoother blending around the nose and cheeks. I thought I could go by with the same toolset I used 2 years ago even 3-4 years ago but I can tell these medium sized paintings would improve a whole lot of I had the right sized brushes. the interesting thing is I do have some smalle rounds but for my painting style small round brushes leave ugly brush marks and make for more uneven blending and cover more pointed areas where the smaller flat brushes would cover a wider brush stroke mark even on a small area as the nose tip, nostrils or lower parts of the cheeks. My only comfort is that this time I have entirely stayed with natural sable brushes and not bothered to venture into synthetic or synthetic natural blends as I did before. They are too stiff for me and their water retention though improving are nothing compared to natural brushes so I'm puzzled over all the youtubers that show the most wonderful and awesome gouache demonstrations using synthetic or synthetic natural brushes.