Figured this is one way to put a few more pics up. Here is one of the leaves browning. You can also see that the inner leaves are beginning to yellow on this let of leaves.

One more of what I'm assuming are aphids?

I don't think you've got aphids on the last one. It looks more like a virus or something.

The first ones could be due to a virus or another kind of disease, but it could be an immobile nutrient deficiency (e.g. sulfur, iron, copper, zinc, boron, manganese, or calcium). If it's manganese deficiency, they might mean your PH is too high (too alkaline), which could mean there's too much calcium in the soil. I would recommend a soil test if you can get one conveniently.

I grew three kinds of tomatillos this year. While some of them did have temporary yellowing up top, the major problem seemed to be that some of them grew all shrively (but they didn't die or anything, and it didn't spread to all of the plants). I'm guessing it was a virus. Your first pictures reminded me of this, but I don't have enough information to tell if it's the same thing (nor do I know what is afflicting my tomatillos).

We have had a really hot, dry here. I don't know if that would have anything to do with it.

We have aphids all over our garden, but I don't believe they like the tomatillos very much (at least compared to most other things).

Well, I'm pretty sure peas are a cool weather plant. Fall or spring depending where you are. Nancy