I don’t know if you are up for flexbox, but it is the way to go. This is a rough explanation. Have a go. Share your read only and I am happy to help.
Assuming that is a full width stretch section:
Create a section and change to flex horizontal.
Add the collection list - set to flex, a width 70vw, one column (flex will set columns at collection item level), limit to 3 items.
Set the collection item to 33.33% or similar. (you will have to weak this for your breakpoints.
Add a div for your CTA inside the hoz section. This will need to be set to display flex vertical to get your centred content. Add your button and text then play with it’s width and flex positioning.