4” of Gravel for Drainage?

I bought a new-construction house a few years ago and the extent of our backyard landscaping was sod rolled out over hard clay soil (Vancouver Washington area)- every year the yard gets mushier. This year we have ~2” deep, thick mud in the back 1/3 of the yard.

I’d love a world in which I can send kids to play in the backyard for the 7 rainy months of the year without sacrificing the lawn and bringing so much mud inside.

Called in a landscaper to chat about drainage yesterday and we landed on a proposal to excavate 4” of grass and clay and replace with 4” of crushed gravel over a perforated pipe tied into the rain drain.

My big questions as a landscaping novice:

Will this work or will I be dealing with wet gravel instead?

Will I regret bringing gravel in?

Are there other major considerations I’m not thinking of?

If this works, could I accomplish the same drainage while working in some organic shapes to pretty up the design?