Actually 160 is pretty good enough for archery, around 6 PD (my test was with a non loomed horn bow)
I'd say, it might be fair trade to cap the archery wpf based on PD. Let's say, 6 PD should allow you to raise archery wpf to 174 max. 5 PD, 160 wpf (maybe?). The reason for this is, PD also lowers the actual wpf; so more wpf is needed to offset that penalty. But maybe that way, we can disallow archers to go with 5 PD, 180-190 wpf; and rather encourage them to spend their points into a melee class.
I must confess that I'm not an expert on archery, so the values I gave are arbitratry. Feel free to discuss it that way. I also do not want any kind of nerfs to archery in general, I just think archers should be encouraged to be a bit less competent in ranged and a bit more competent in melee. cRPG might be the mod that is famous for it's freedom in builds, but some restrictions are needed. Sometimes less diversity is better for gameplay.
Side note: Shield weights should be reduced a bit too. Although being with a shield gives better protection against ranged, it also slows you down too much to effectively deal with them. Although shielders should not be necessarily the ultimate counter to archers, they must be a bit better to them than they are now. I also agree with kinngrimm about steel shield, being the least valid choice in battle. A high tier shield should be better, especially if it requires 6 shield skill.
By the way, one must not forget the scenes (by your calling: maps) while considering balance. Some of the scenes are cities, some of them feel more like open terrain. Archers and Cavalry tends to do better in open terrain, infantry tends to do better in close combat oriented maps; mostly city maps or maps with a lot of objects to hide. People must know that they must change their tactics heavily to adapt to the scene in play.
As an infantry, what I do is mostly defending archers in open maps. In open maps, good archers are the key to victory. Because they are the only asset to the team against (by the following order) cavalry, archers and especially horse archers. An archer can easily shoot down enemy cavalry. Later on in the round, they are essential to deal with the remaining archers and horse archers (to prevent kiting). Cavalry is also important to prevent the foot archers to kite. In close maps, things are almost entirely different (depending on the closeness of the map). The rounds will mostly be decided by melee this time (again, depends on the closeness of the map).
I'd say, non-shield infantry is the most disadvantegous class in open maps. Vulnerable to missiles, check. Dangerous cavalry that can attack from any direction, check. It is natural it might feel like a nightmare. But again, that is something you should consider when choosing this class. It doesn't mean there are no ways to prevent this, however. Those are teamwork and using the map to your advantage. Even in open maps, there are a lot of objects that gives cover from ranged and cavalry. That is also where friendly archers go to seek cover too. Since an archer is my best way to defeat my counters, then I prefer to guard it. In close maps, I am the kind as long as I can best the enemy infantry (which is your measurement of skill, so I believe you are good at it).
In any case, armor and ironflesh gives a lot of survivability. I can't say much about xbows and archers, but Horse archers do like 1/8 damage to my 21/21 character. They are not much of a threat from my perspective, especially if I succesfully defended a friendly archer. Even not so, there are objects I can use as cover and I do not have to go to them. I prefer to let them come to me.
