One of the major issues when it comes to equipping the right armor pieces is that it suffers the Warframe problem of not properly explaining how it really works. There's really need to be a guide on how armor works, and it can't be all: "You need "Set" this and "Set" that." Not even the online manual properly explains how armor works in the game, because simply going on and on about Sets doesn't really explain anything to a new player. Let me explain on how armor pieces look like to the new player myself but was part of the beta:
When a new player finds a piece of armor they will see: "Armor Name" "Armor Piece" and then 'apparently' what kind of defense it raises like "Melee Defense." So the player will go on thinking "This piece of equipment will only increase Melee Defense and this one increases Range Defense, and the last one increases Tech Defense." And they will just continue to play the game with that mindset, never realizing whether it's true or not that the armor pieces affect the other Defenses besides the one that's listed before they figure out that they can look into the piece of equipment with more detail.
When they do look at these other details and find out the other type of defenses are with the one that's listed, then the player is then left with the question, that's probably misunderstood, "If my armor piece has these types of defenses then why is Melee Defense is the only that's highlighted?" So other questions will be pondered for a minute about why PSO's defense is the way it is before simply deciding to move on with the previous mindset that "If an armor piece says it does Melee Defense, then that's what it will do" and will focus on getting pieces of armor that has the highest defense stat of that particular type and won't think about anything else.
I think I understand why that's not much of a good thing to think like that, but you have to understand that most people won't understand what you mean by gathering armor sets and will probably be very hesitant to get rid of pieces of armor that "maybe only raised that particular defense" in favor of a set of armor that only does one type of defense like Range Defense only. Which will make them ask "Why would I get rid of my other types of defenses for a set that does only one type? That sounds suicidal..." This means you're going have to explain or show a guide of how armor actually works and why a complete set is beneficial besides "They give Set bonuses," which will probably make many, probably the ones who won't even go this far online, go "Yeah, not enough to sacrifice ___ defense for them." That way players will learn something new along with understanding a part of the game that doesn't help in explaining "some" things well.