Said where?
The limiting factor on all traditional bows (self or composite) is the user not the bow. You can easily make a 300lb long bow or a 300lb composite bow but nobody would be able to use them.
The difference in design comes from the difference in materials available. Those with access to suitable wood (Ash or Yew generally) used straight bows as they were easier to make and were less susceptible to damp. Those without suitable wood made composite bows instead.
MY GOD. And u are beta tester??? Shape of the bow is essential to bow performance. You need to learn some physics. It doesnt matter how strong you pull the string if the the bow cannot project that power into the arrow. Simple bow design (short bow, bow, long bow) loses a lot of that power on release and just a portion goes to the arrow. On the other hand recurve bows have the best efficiency cus it puts a lot of that energy into the arrow. You need less power to perform equally or better with recurve bow than with long bow. Composite bows are also stronger that simple bows but it depends on design too. If its simple design, they are more powerful but require much more strength of the archer to pull the sring. Composite recurves are maybe the best, but they are hard to master.
The reason why Europe didnt use composite bows was the method of binding the different materials to form a bow - it falls apart in wet climate, and most of Europe is wet. Composite bows are more common in arid areas (lets say Asia). And now when u mentioned it, simple bow design is easy to make and it should be cheap (lol @ crpg prices...).
Now please go read a bit about archery physics and then start talking about "OMGF LONG BOW IS THE BEST". Long bow sucks, end of story. Its all about English ppl that have rather small penis when it comes to their culture. Long bow only has marketing, and to back up the "cultural small penis" just take a look at English archaeological elite when Ausies found a structure older than Stonehenge with the same purpose. There are many more examples how English try to "prove" that they are either the best in something or 1st or both.