How do you want this beer to end up? Pale ale is kinda all over the map as it has evolved over time and popular hops have come and gone. Cascade/centennial will give you a classic APA profile but for a lot of people it's going to taste dated because it is one of a handful of hop combos that were in most APAs through the 1990s-early 2010s. Cascade/cashmere would be a nice blend IMO.
I don't profess to be a master of pale ales but if it were me trying to making something of a modern but not hazy APA I would bitter with centennial to around 40-45 IBUs and then do a 40/60 addition of cascade/cashmere at a rate of 1oz/gal as a big whirlpool addition. No late boil, no dry hop. Dry hop if you feel it is lacking in hop flavor but I don't usually find it necessary with this rate and timing.