Currently, armor values are so low and people hit so hard with small weapons that everything you are interested into is sheer speed. Strenght build might be succesful, but usually either the player behind is skilled or the char is crushthrough oriented.
-ATH perhaps the better skill IMO. Makes you able to choose fights, to reliably kill groups of enemies (running in and out), to surprise attack and play with weapon reaches
-WM the increase in wpf seems marginal, but the speed given still is a big advantage (feints)
-Shield, probably at the same level as PS, depends on the str/agi ratio and the shield you plan to use (small shield users like me appreciate that skill)
-PS well, good but usually above 4-5 you will two shot most people
-IF I found it the most useless among melee skills. If you have money to spend on armor, why not. But you can be as succesful with a cheap equipment and no IF.
Note: I see shield+1h fighting as, well, fighting. I usually die against shielders with a "turtle" behavior, because my goal is to kill, and their's is not to kill but to survive (or at least they act so). So I use small and fast shields (but not the jedi orange presses, ffs), usually the knightly heather shield. It gives minimal protection to arrows, very few health points, medium armor, but is very fast. This type of shield is succesful when played in an aggresive manner (or at least it's my impression). It's very good for fighting against disadvantaging numbers.