Chaplains are angry librarians wearing black;
Librarians are nerdy chaplains wearing blue,
apparently.
Specialists are an opportunity to show that the various personnel have different experiences. Making them all upgrade characters at one level and squad buffs at another is just making them into differently colored health potions.
Apothecaries, Chaplains, command officers, Librarians, and Techmarines are all trained differently and have different paths.
Psykers are dangerous and start their specialism immediately because they need to be controlled. They also do not need to learn the profession of infantry squad tactics; they provide intelligence.
Chaplains, on the other hand, are cheerleaders and drill sergeants, they are intimately involved with the life of their companies and can be picked straight from squads after having taken some night classes and sweeping up the chapel in the afternoon. The most description is an old one:
Chaplains are drawn from the ranks, although only Marines who have earned both Merit and Devout badges are considered for a Chaplaincy. These awards may be displayed as actual badges, or for example as diagonal stripes painted across the right shoulder pad.
As a first step, a Marine is singled out to aid the Chaplain of his company as a Novice (or Initiate - the terms are almost interchangeable). Duties often involve little more than helping during company rituals, but deep study of the liturgies under a Chaplain's personal tuition is also necessary.
Should a Chaplaincy fall vacant, the most advanced and promising of the Initiates is sent to the Solitarium. This small cell is situated in a secluded part of the monastery and here the Initiate meditates and fasts for a time. He may be left there for up to a week, while his investiture by the Reclusiarch and the Master of Sanctity is prepared. Then, in front of the whole Chapter, he is formally given his symbols of office and presented to the company who are now under his spiritual guidance. At this point the new Chaplain takes the name of his predecessor.
When a Chaplain is killed in battle a formal ceremony often has to wait. The senior Initiate immediately takes the helmet and shoulder pads of the Chaplain and dons them. From the moment he puts on the old Chaplain's war-gear he has full authority as one of the Chapter's spiritual leaders. He is formally invested as a new Chaplain only when the battle is won and the dead are absolved.

Originally Posted by
Askari
a Reclusiarch would keep the rule as it is, and a Master of Sanctity would re-roll 1s to hit even in turn when they didn't charge.
For Librarians, a Lexicanum would wield a non-armour-ignoring Force Weapon (Force Staff, Focus Rod, whatever) and use one power
Reclusiarch is a headquarters rank, a cathedral dean who runs the shop for the Master of Sanctity. How many types of force weapon should Imperial lists have? I don't think 40k gameplay needs this.
I have a whole system; all my parents' cultivation and all the calories or time I have ever consumed have been spent getting it right.
Basic codiciers cannot really be HQ units anyway. The codicier is demoted to a client unit, like servitors or command squads, and he can't be used as an HQ. All HQ characters allow one of them to be taken as, for instance, an adviser to a captain or the charge of a chaplain. His leadership is nine and he has only one power. This makes him ambiguous between a lexicanium and a codicier.
Chief Librarians can't be that different from epistolaries, so they can also share a profile, this time with bs5, i5, three attacks, and ld10. They come as HQ choices, cast two powers per turn, and can make available a codicier just like any other HQ.
The qualifications for being a chaplain are being an especially charismatic battle-brother who isn't as good at commanding armies. A trainee chaplain is any guy in any tactical squad or other squad. They are not special; special rules for novice chaplains are reductive and mean very little. Going up the chain, chapter cults should be the most distinctive difference between chapters, and reclusiarchs or masters of sanctity all need to be special characters like Iron Fathers, Templar chaplains, sigmarite-style warrior priests, Ultramarine drill officers, or Promethean chaplains to have any real use.
It's fandexy and this thread is quick-fixy, I get it. Squad upgrades for specialists just denigrate the offices, is all I mean.
can take Force Dome or The Avenger
right, because it would be weird if a lexicanum could teleport or throw warp storms. You take the opportunity to write modest machine curse or avenger type powers for the basic librarians, and chapter-themed powers for the seniors.
chaplain wargear and options, close combat weapon instead of crozius
A rosarius is supplied by the ecclesiarchy as a token of understanding to chapters' reclusiams. If anything, they would have the crozius and not the rosarius. Do they become henchmen accompanying the chaplain, what is going on?
It's true, this is vastly better than just painting an anonymous tactical squad member a different color.