Transferring files, fastest way to

When one is transferring files using a MBP specifically (or any Mac), what is the fastest way to do that? I am of the opinion that if I am trnasfering a lot of data or large files that it is best to transfer them in smaller peices then to transfer the whole thing at once.

For instance, if I have a folder (Main) that I want to transfer and it is 100 GB and it has say 20 sub-folders, I will make a new folder in the receiving drive (Main) and transfer say 4 of the sub-folders to the receiving Main folder and then another 4 folders and another 4, etc so that all 5 transfers are happening at the same time as opposed to simply doing one transfer of the Main folder from the initial drive to the receiving drive.

This may come from my past history of sometimes having a transfer stop in the middle or crash and having to go back and start all over again. Still it seems to me that my computer transfers faster when it is doing a lot of small transfers as oppose to one big one.

Am I crazy? Is this true or false or does it really matter one way of the other? Is there a limit to the number of transfers that can happen simultanieously and still be faster?

BTW, I am using USB external drives in this example, not that it should matter. Now that I say that, does it matter what the speed of the drive(s) are? LIke, is it better to transfer from a slower drive to a faster one or visa versa?

Thank you in advance!

Cheers!

Gar