Using the guys on tour is an unfair comparison. Most of those guys can go from being a stroker to a cranker. They're able to adjust to the conditions and generally find what works for them.
Someone mentioned Walter Ray. He generally plays straighter, but I know I've seen him swinging the lane on rare occasion.
As far as your more amateur bowlers, neither style is the end all be all. It depends on the lane conditions, and the bowler themselves. Also depends on what you are using to compare who is better. Season long avg? High Series?
The Crankers get more carry on THS generally cause they have the extra power and high entry angle to create pin action. On the flip side, they have blow through a rack and leave some nasty spare shots.
Your strokers are generally more consistently leaving 9 counts, but don't get some of the high and light carry that the crankers do.
No one style is better overall. It's just a tool for each individual bowler to use.
--------------------
First one to leave 15 ten pins wins!