17 years in game, about 70 hours into the playthrough, and it seems that Japan has almost reached a stalemate.

Just a total of 14 clans left, and the one I am part of (Oda) is the strongest (17,8k). However 7 other clans are also pretty strong (between 8,8-11,2k), and now it seems that no real progress is happening. The wars cycle around in good order and we are often fighting on three seperate fronts of the kingdom, but the tug of war is like a tide and for every castle we take on one front another one falls on another.

Lately I have been trying to hold one front by myself, and I have lost count over how many 1v5 fights I have had to try and stop the enemy from advancing.

I capture as many lords as I can and store them away in my castles and cities, but they escape at a frequency that makes me believe that my prisons have revolving doors..

Is there any way for me to escape this never-ending slog? Is there a way to recruit lords over to your clan, even if you are not the clan leader? Should I just start executing any lords I come across (and begin my villain arc), or will new one spring up from the ground just as fast?
Is there a way to hinder/damage the enemy clans from just bouncing right back after every war? It seems they have an endless stream of resources and can muster huge armies that they relentlessly sends my way..

I am not so keen on spending another 70 hours just acting as a rock upon which the enemy clans break if no real progress is happening. It feels like the only thing that might happen next is that any of the smaller clans that are left (1-3k) will be swallowed up, and eventually two of the bigger clans will help each other with devouring another big clan - making them a real threat to my Oda clan. Then the slog might become even harder..

Any help or tips on how to proceed would be greatly appreciated!