Doesn't matter ,in the end its the sum total that matters..
Naruto received hell for being a jin and had to go through a gruelling training to achieve KCM and Kurama's consent( another difficult task) for TBM.In the end he earned it,if being a bijuu meant you had power that easily you'd have perfect jins like bee and Naruto everywhere but Naruto and bee are the only ones out the several jin that have existed.Hence,they earned their power.
Their power is not borrowed, it has been earned through sweat and blood.They did something that 99.99% of the NV populace including Sasuke is incapable of.The suffering they went throughtalso counts in.What they did was not as easy as having an eye transplant ot dna implant..
Also,this would make juubito's and juubi madara having "borrowed power" without having to fight a mind battle with the juubi.