Quoted from the following links.
Note: For Tableau Server 10.2, you need a minimum of 2 physical cores. If you are installing on an Amazon EC2 instance, this means 4 vCPUs. For more information, see Amazon EC2 Instances.
Since your instance types are,
c4.2xlarge 8vCPU m4.2xlarge 4vCPU
they meet the minimum hardware requirements.
As for performance, it's hard to say.
Just start from minimum and adjust the sizing accordingly.
Some links for your reference.
("Manually determining the number of cores on your computer" part is particularly useful for me)