Mobility and stretching are different.
Where your shoulder is in the socket may need addressing.
If it is forward in the socket you’ll hit bone on bone earlier than you should.

Are you working up/down stream of where you see the issue?
Tight lats need addressing
Episode 297: Liquid Kayak Camp and Lat Hell
Episode 80: Best Shoulder Mob Ever

How often are you addressing your hamstrings?
Multiple doses throughout the day may be needed in the beginning.
Have you watched any of the hamstring episodes?

If you are working on something and not seeing improvement you need to re look at how you are addressing it.
Pro Episode # 21 – Pro-User Request Friday: Not Seeing The Change? You Need a Systems Approach.

You don’t want your femur in the front of the socket.