Is the impasse impassable?
I don't really care. It is up to the company. If they want to keep on losing the more joiner pilots keep dreaming that the package is competitive. If the company cuts the conditions of the more senior guys the company with have to decide that they can accept the accelerating rate of resignations.
The key thing to me is that no agreement is even considered if one group of pilots is expected to pay for improvements for another group. Market forces are finally giving pilots of all level options we haven't seen before. If the company wants to change things it is up to them.