You can absolutely access multiple components in a system, for some reason you think a component and a system must have a one to one relationship, when really it’s many to many.
The only caveat is that you have to think carefully about the order that some of your systems are executing in the game loop, since you want to make sure component data has been updated appropriately for later systems to act on.
ECS is really the best way to make games. It lends itself well to rapid iteration and experimentation of new game concepts.