Gentlemen, we can rebuild him. We have the magic.[3.5 Monster Class]

[Tanuki Tales]

I think that the Golems that grant DR = Str should instead add their Str mod to their DR.

Here's an example with a base 18 Str score and a base race that gives +2 Str.

By the 3rd level of this class they would have a Strength score of 25 and DR of DR 7/Adamantine. Any other Half-Golem would have only DR 1/Adamantine so yeah, it looks real good right now.

Now let's take a look at the same two characters when they're 14. The former would have Strength 28 (assuming its dumping all of its ability points to Strength) and DR 9/Adamantine. The other character would have DR 7/Adamantine. So while the former still has more than the latter, the 6 point gap from level 3 has changed to a 2 point gap.

Finally, here's a look at 20. The former has Strength 30 and DR 10/Adamantine. But hey, guess what, so does the other Half-Golem. And you know what else? The other half-golem didn't have to dump all 5 points it got from leveling into Str to reach that high a DR.

Now sure, this doesn't take into account using the ability to spend more gold on your graft to bump scores or using gold to buy permanent increases to Str or taking classes like War Hulk to get your strength up. But on the flip side the other golem type character didn't have to direct their entire character build to buff up one stat just so that one of their body material type's major features wasn't rendered useless.

Edit: Some may say that this would be overpowered, but compared to monsters that are at CR 20 or higher, that's actually just on-par with them and those monsters also tend to have other things like Fast Healing or Regeneration or casting, etc.