Will having more scan power increase the chance that you will find rare NPCs?

It affects the NPCs you can find; some have minimum scan values (such as Blade Harvesters and T.O. Troop Carriers having 50 cloaking).

you only have to have scan equal or greater than the cloak of the NPC desired for it to be tossed into the pool of NPCs that have a chance of spawning...

more scan beyond that NPCs cloak doesn't increase the chances of that NPC appearing... rather, if more scan adds more NPCs, it could potentially decrease the chance of an NPC with less cloak from appearing, versus having just enough cloak for that specific NPC

make sense?

so scan power undirectly affects the NPCs you get?

No, it DIRECTLY affects which ones you get. Maintaining scan below 20 eliminates Styll Assassins and Tech Collectors from spawning. Maintaining below 50 also eliminates TO Troop Carriers and Blade Harvester (Rogue Labpods also I believe). Below 500 eliminates Shadin Hypergrids.

Scan value against NPC Cloak is a catch22... To find the good stuff, you need enough scan that you end up getting the bad stuff too.

aye, as darth said, it has a direct affect

go to the wiki
find an npc that is not spawned at completion of a mission... (completion spawns sometimes have massive amounts of cloak... but it doesn't matter because they're only spawned by the mission regardless of if you have enough scan)
if there is cloak on the npc, you just need at least that much scan to see it.... 20 times that much scan doesn't make it appear any more frequent... (and as i said, the higher your scan, the more npcs that have a chance of spawning, so the lower your chances of finding a specific type)


(on a sidenote: level has a direct affect too.. have to be high enough lvl to see certain ones... and after a certain point, lower level npcs start disappearing)


so in closing...
if you have scan less than the cloak of an npc, that type won't ever appear
if you have scan equal to or greather than the cloak of an npc, that type is thrown into the pool of selectable npcs
all npcs in the pool for a particular rarity (common, uncommon, rare, extremely rare) have equal or near equal chances of being found
(i say near equal because some experiments have shown some npcs being favored over others)