Sheep's grassland

So i wanted to draw something else than cats all the time, so i decided to try to draw animal that i never draw, i decided to draw sheep, i also wanted to draw some landscape.

When i think about sheep I think about Northern Ireland, the country i live in, so I draw it as if this were Northern Ireland, so it's very green, it got plenty of grasslands, hills, sea and gorse

I don't think i did good job with those sheep, like why does this front sheep look so empty?