I believe there is a large amount of misunderstanding.
To calculate the batting average in any pitcher/hitter matchup (what many people mean by "normalization"), WIS performs a calculation that includes:
-the hitter's actual batting average;
-the hitter's league average batting average;
-the pitcher's actual batting average against; and
-the pitcher's league average batting average
That's all that matters (as far as the player's numbers go).
Now, WIS provides a couple of stats in the search center to help with your team building:
"+" stats are relative to league average. This is useful in single-season progressives since everyone is compared to the same league average (actually, there are two league averages--AL and NL--but ignore that for now), and so this makes it easy to see where the player falls relative to average. However, when comparing players ACROSS seasons, this number is much less useful since the league averages they are compared to vary widely. This only gives one of the two pieces of information you need.
"#" stats combine BOTH pieces of information you need by essentially saying what this hitter would hit against a notional "average" pitcher. By comparing all hitters to the same baseline, and using both pieces of necessary information--his batting average and his league's batting average--we now have all we need.
You can thing of "#" stats as combining "actual" and "+" stats.
Now, there are many other factors and non-linear aspects of this that could mean that "#" stats are not 100% the be-all, end-all. However, these are minor and so you will be better off in nearly all cases using just "#" stats instead of some combination of "#", "+", and "actual" stats.