Good start on the face so far. The contrast is there
It also seems quite matte so I guess you found a way to get rid of the glossy finishes.
GW paints are quite good (I like the reds) but also pricy and I don't like their "new" pods. I have never really tried Army Painter. Just own one single brown tone that didn't really impress me but you can't judge a whole paint range just by one color. I own a lot of Vallejo paints since they were cheaper then GW back in the days (and still are) and when GW changed their color sortiment and I couldn't get my beloved "Scorched Brown" anymore, I switched to a manufacturer that was consistent with his paint range and wouldn't throw it over every few years.
But I guess all paint ranges that are out there, designed for miniature painting, work well when you figure out how to make them work for you. It depends more on personal preferences and habits. For me switching from the old GW range to vallejo was quite challenging since most of the Model Color paints are more opaque then GW used to be. So it took some time to adjust my painting habits. On the other hand I was quite disappointed when I got the Scale Fantasy and Games range since these paints are more semi transparent and need more layers to build up a uniform color. Although they work really great with glazes and have some really beautiful vibrant tones I'm not a fan of all the layering and glazing I need to do to get the effect I want. The regular Scale 75 paint range is too matte for my taste and you have to shake them really long and hard -> that was a big downside for me as well.
TLDR: Every paint range got its pro's and cons so just try some out and find the ones that fit your style and habits. The best tip I can give is: Don't by too many tones, you won't use em anyway. From the over 200 paints I collected over the years I probably use 10-20 on a regular base. The rest is mixing. I bought a lot of tones to follow along some tutorials but often I used them just once and some even never since I forgot about the tutorial or found new projects.