Succulent arrangements can be so much fun to put together! Planting your succulents close together will keep the arrangement tight, but planting them further apart will not cause them issues, as long as they’re not too far apart.
It’s really up to you and how much you want your succulents to grow and spread. If you’d prefer they stay the same size, a tight grouping is the best option.
When planting further apart, it’s possible that you will need to water them more often, because there is better air-flow and the soil will dry out faster. This is important for your succulents’ health: good air-flow allows the soil to dry out faster, preventing root-rot.
Another thing to keep in mind is the size of your pot. If you plant your succulents in a pot that is much larger than they are, they will focus more on growing long roots than producing a larger plant.