I have a tool for throwing multiples, which I consider indispensable: a throwing gauge. You can buy throwing gauges, but I made a simple one for free out of a broken gooseneck table lamp. I removed the lamp head and the electrical cord. I attached a metal pin (a leftover part from disassembling the lamp) to the end of the gooseneck with a blob of electrician's putty. Then I secured the putty and the pin in place with electrical tape.
Here's how it works ... throw one pot to the dimensions you want, taking time to measure it carefully. When done, position the throwing gauge so the end of the pin hovers right above the rim of the pot.
Now, the pin guides you as you throw all the subsequent pots. It gives you both the height and the width of the rim. Unlike a ruler or calipers, you don't need to stop throwing to check your progress. Just aim for the pin. And here's a trade secret from a production potter ... when throwing multiples, the only dimensions that matter are the height and width of the rim. The other aspects of shape are not terribly important. As long as the rims are the same height and width, they will read as matching multiples.
To all of you who still think "ugh" at the thought of throwing multiples, I say "keep practicing because you don't know what you're missing."
Good night, pots.