I follow your reasoning. I think the averaging calculation (divide by 2) only applies if you were to mix each product according to instructions in two separate gallons and then combine them. However, my ability to evaluate fertilizer strength just got thoroughly trounced in another thread, so I'm reluctant to make any pronouncements. It was about total ppm calculations, though, not exactly the issue here, but related. Here's a calculator for ppm, if you're interested.
https://firstrays.com/fertiliz...
Nonetheless, I am certain that your potted tomatoes need more nutrients than those two products provide. 😊
