> you can never have too many sources of entropy
This is so true. And the beauty is that with algorithms, we don't even need to know much about the entropy to be able to extract it.
There is the Von Neumann method of generating an unbiased coin from a biased coin. Of throwing it twice, and checking if you got HT or TH. And completely discarding all HH or TT results. It doesn't matter if the coin you are using is 20% or 80%, the result will be a true 50/50.
There are more modern algorithms that can be even better (in that they need less coin tosses if you have a very unbalanced coin).
And then there is modern cryptographic hashing. Feed it all the bits you can. Collisions end up only happening in the real world if every single one of those bits is identical. So if you have actual entropy being fed, that cannot be controlled, predicted, or replicated, modern cryptography tells you that the end result is unique.