Yes, it makes sense, and I reckon it is all one underneath. when we lived in a coach with a wood stove I used to look out for old holly bushes. They often grow like that and then get 'standing logs', an upright that dies back and dries out without falling. Shake it rhythmically and it will snap off, a good bit of dry, hard wood. For this reason, and looking at the cuts already made, I reckon you could take out a fair number of those uprights and you will see new growth coming, then you could reduce a few more.
I don't think you would get away with splitting and replanting like an agapanthus or a rhubarb, too woody, too deep rooted.