I used to layer my kicks but I tend to find you create more problems than you solve.
You introduce phasing issues and also watch those start points and badly clipped samples.
IT works but do be careful, make sure the samples all trigger correctly and check for phasing.

I tend to just use 1 or 2 kicks now, never or very rarely samples, I`ll use synth kick generators to create the right kick or kicks for the job.
Maybe a deep 808 style for that round low end, and then a slightly more aggressive 808-ish for some mid thwack.

If I am using low sub then I will set a very hard low cut on the kick (before compression) to scoop out room for the sub.

The current mnml trend is softer, deeper sine kicks (think 808) with a little snap/click on top.
These are very easy to create and can sound nice with creative compression.
They tend to be focal points of tunes so just make sure there is a lot of room for them, if that is the route you are going down.