What does the phrase "more wood behind fewer arrows" mean?
@Mehper's answer is right - I would like to add more context.
The background seems an oft-used phrase in Sun Microsystems by the former CEO, "all the wood behind a single arrow" which means focus on a single product and be the best in it.
A graphical description of this is found on this blog (see the picture too),
When deer hunting ..
Real men bring only one arrow. They know how to aim (and they remember to take plenty of time when aiming), and they put all the wood behind that one arrow.
If you're really good you know how to make the maximum utilization of the available resources, be it one arrow or more.
So on to the current phrase, the core motive for "more wood behind fewer arrows" is focus.
It means focus on the priorities, be good at those priorities and remove the non-priorities.
Arrows require two ingredients: 1) wood (to give them "flight") and 2) arrowheads, of metal or possibly stone, for "striking."
One strategy is to make "lots of" arrows (and blanket the enemy with them). But the problem is, you may often be short of arrowheads. Hence you need to make "fewer arrows."
When you have limited "strike" capability, you need to make sure that each strike counts for more. The way to do that is to put "more wood" (heft), behind the few "arrows" that you do make.