Testimonial section using CSS Grid

I am not sure what is best practice for styling the individual testimonials sections. I chose to use "nth child" to select each and apply individual styles. Another approach could be individual utility classes for each. Which is the more standard approach?

It was my first time using grids for a design. Being able to span content across multiple cells (name?) and being able to rearrange the order of content visually will be very useful.