If you are working with motion graphics you are going to need a powerful rendering engine to process your project. The clock speed is basically the speed of each individual core on the processor. You can pretty much get two kinds of processors, ones that have a lot of cores or ones that are very fast per core.
It's gotten pretty close nowadays and you can get systems with basically the best of both but it's going to cost you a premium because each one of those factors is a bit more expensive.
Intel tends to play more on the low core count higher clock speed and AMD is more on the range of the larger core count, lower clock speed more threads for processing versus faster processing of each thread