It'll work, but as BH said, the case body has to be managed as well.
For your approach(seperate neck & body sizing), which is totally fine, you should use a 'body die' instead of a 'FL die', so that each action is truly seperate.
This seperate sizing can also be accomplished in one die with a 'FL bushing die' which is merely a body die with a bushing for neck sizing: Full-Length Bushing Dies and Die Conversions
With this you could chose to remove the bushing for favor of collet neck sizing.
I use JLC dies, and prefer bushing systems over anything else to date..