San Salvador/Norte vs. Invierno?

I am planning to do the Camino Frances this summer (late June to early August) with a group of four. Last year, several of us completed the Norte/Primitivo. I absolutely loved walking through the coast and the mountains, however, we do not want to rewalk anything. We are looking into either doing the Invierno or the San Salvador paired with the second half of the Norte from Oviedo. Because of our timeline, we would have to take a train from Burgos to Leon to accommodate the Salvador/Norte combo. Any insights on the merits of one approach versus the other would be greatly appreciated!