Warforged Repair Kit Vs. Masterwork Smithing Tools

[Yogibear41]

If one is using Craft(Armorsmithing) to repair warforged, is there any reason to get a Warforged Repair Kit if you already have Masterwork Artisans tools for the craft check? They both give +2 circumstance, which doesn't stack as far as I know.

[Troacctid]

Circumstance bonuses do stack if they are from different sources.

[Yogibear41]

Isn't there a rule that if they are from a similar source they don't stack though? Both seem sort of similar.

[Troacctid]

That's if they're from the same source. Similar is not the same.