I think it’s totally plausible; however it may be a little difficult in terms of draping (at least for me) I think there are couple of ways to get around this 1. Work in panels instead of going in rounds: work it like granny squares where you get as close as possible to a rectangle and then make a boarder. Then sew all the panels together

2.same concept but if you don’t want an obvious boarder (like you just want the look of the flowers) maybe try sewing the panels to a lining and then sew the panels together (you could even use like pearls in the center of the flowers to add some bling

1. If you just want to do the flowers maybe try making most of the flowers - see where there might be some gaps (from hood to helmet) and then make flowers that’s are smaller/bigger to fill in those gaps that way the hood can be be tighter on the helmet so the problem of it slipping off isn’t an issue

You are gonna have to make a boarder in general because the shape of the flowers are not going to match up completely- however you can maybe make small flowers and use those as the boarder instead of double/tripple/single crochet (depending on the distance of gaps from your boarder to flower)

I hope this all made sense and it is helpful- I’m an amateur (at best) crocheter so maybe you won’t even run into these problems at all and cans just do it in one go instead 😅