Hatrix, I should add that I was going on the assumption that you might have overestimated the weight of the bass you're catching. A 12" bass with an average Wr will weigh closer to one pound than two, so I was estimating that you have been catching one to two pound bass, perhaps a three-pounder here and there. I wouldn't think three-pounders would be common with that many bass in a pond that size. Have you been weighing them? If so, two pounds for 12" is extremely good body condition, and they may not need thinning much, though they definitely will grow faster if some are removed. I don't think I've ever seen a 12" bass that weighed two pounds.
If I'm correct and you've just been estimating their weights, you probably don't have many bass over three pounds in the pond right now, likely no more than a handful if that. You might not have a single bass over four pounds in the whole pond. But thinning them, by either method, will result in more forage for the remaining bass, and they'll grow far faster, and bigger, than they are now.
