Vaer, or Marathon... Neither Seiko nor Hamilton make real field watches, or the best value.
Marathon makes actual military issue watches.
Vaer makes much better value field watches than Seiko, and apart from vintage history, Hamilton.
Out of those two, I actually bought the Hammy. I ended up selling it but it was pretty nice watch.
better design would go to Hamilton
only thing the seiko has is the extra complication of the day. price and availability would be the next deciding factor. I'd pick Hamilton out of the 2
A sucker for watches living in France