Carbinegirl Welcome.
I have wore out a tumblers tumbler
https://ads.midwayusa.com/case-tumblers/...e+tumblers and replaced it a
https://www.youtube.com/watch?v=Gho5ozsiEDs and I use the SST pins and the ceramic combined but the volume of cases I clean at times when I'm on the road that will fill a 5 gallon bucket sometimes I ordered a second tumbler, the Frankford Arsenal that has a larger capacity that I actually like better then either the Tumblers Tumbler or the Rebel 17 so I use the pin/ceramic mix it and just the ceramic in the rebel. The Arsenal tumbler turns a lot faster then the Rebel but it does not damage the case mouths more or less then the rebel.
Both pins or ceramic does a fine job cleaning the brass. But using the pins you have to do something to separate the pins so you don't loose to many also the ceramic media. Pins you can use a Magnet like this
https://www.amazon.com/SE-PM6550-Magneti...dpSrc=srch and one of the classifiers that has a 50 mesh screen that will fit a 5 gallon bucket to drain the water and hold the media so you don't loose it.
As far as your question about having to resize has nothing to do with using the tumbler. This is a re loading thing you will or will not have to do for a proper bullet retention in the case or what works best for the load your using.
Something to think about ........................Kurt
I might add........The Rebel 17 is a lot quieter to run if noise is a issue.