It's not entirely clear but I don't think it's one or the other. What they are recommending, I think, is a fuse for each individual power supply.
The number of units per circuit breaker is just for your reference, and is a maximum number of power supplies you can feed from each type of breaker in order to avoid nuisance trips from the inrush current on power up. In other words, up to 19 of these power supplies can be powered from a single 16 amp C or D curve breaker.