The problem with quoting from the SN is that Bhikkhu Bodhi’s non-free translation is really the only game in town (excepting old non-free PTS translations perhaps?). I’ve both the electronic and hard-back versions from Wisdom that I had to pay for (the feel of paper is nice but my ebook reader packed with electronic texts tends to be more practical a lot of the time than lugging around a heavy tome ). Otherwise the free online coverage is very patchy (via some anthologies etc.) Luckily, Bhante Sujato’s free Nikaya translations should remedy that in the near future!
Cutting and pasting large sections of SN48 would get this site into copyright hot water. SN48 is internally very consistent, though, in how it treats this topic. I’ll give a few extra passages.
Samma samadhi seems synonymous with the four jhanas in it. For example, SN48.8 gives a brief summary of the five faculties:
“Bhikkhus, there are these five faculties. What five? The faculty of faith … the faculty of wisdom.
“And where, bhikkhus, is the faculty of faith to be seen? The faculty of faith is to be seen here in the four factors of stream-entry.
“And where, bhikkhus, is the faculty of energy to be seen? The faculty of energy is to be seen here in the four right strivings.
“And where, bhikkhus, is the faculty of mindfulness to be seen? The faculty of mindfulness is to be seen here in the four establishments of mindfulness.
“And where, bhikkhus, is the faculty of concentration to be seen? The faculty of concentration is to be seen here in the four jhanas.
“And where, bhikkhus, is the faculty of wisdom to be seen? The faculty of wisdom is to be seen here in the Four Noble Truths.
“These, bhikkhus, are the five faculties.”
And, generally, the pattern in SN48 seems to be the stronger the faculties the stronger the attainment, e.g. in SN48.14:
“Bhikkhus, there are these five faculties. What five? The faculty of faith … the faculty of wisdom. These are the five faculties.
“One who has completed and fulfilled these five faculties is an arahant. If they are weaker than that, one is … a faith-follower.
“Thus, bhikkhus, one who activates them fully succeeds fully; one who activates them partly succeeds partly. The five faculties, bhikkhus, are not barren, so I say.”
There are other interesting passages in there about the faculties. SN48.50 describes the sequential aspect of the faculties: how faith leads to energy, and energy to mindfulness etc. Here’s a snippet:
“It is indeed to be expected, venerable sir, that a noble disciple who has faith and whose energy is aroused will be mindful, possessing supreme mindfulness and discretion, one who remembers and recollects what was done and said long ago. That mindfulness of his, venerable sir, is his faculty of mindfulness.
“It is indeed to be expected, venerable sir, that a noble disciple who has faith, whose energy is aroused, and whose mindfulness is established, will gain concentration, will gain one-pointedness of mind, having made release the object. That concentration of his, venerable sir, is his faculty of concentration.
The description of concentration here is admittedly much briefer and vaguer (no direct reference to jhana). Interesting too how the memory nuances of the word “sati” are emphasized.
There are several mentions later in SN48 about wisdom being the chief among the faculties, stabilizing the other four (described as being like a “roof peak” in SN48.52):
“It is, bhikkhus, just as in a house with a peaked roof: so long as the roof peak has not been set in place, there is as yet no stability of the rafters, there is as yet no steadiness of the rafters; but when the roof peak has been set in place, then there is stability of the rafters, then there is steadiness of the rafters"
There are also some intriguing descriptions of people whose faculties fall slightly short of being full arahants, e.g. in SN48.16:
“One who has completed and fulfilled these five faculties is an
arahant. If they are weaker than that, one is an attainer of Nibbana in the interval; if still weaker, an attainer of Nibbana upon landing; if still weaker, an attainer of Nibbana without exertion; if still weaker, an attainer of Nibbana with exertion"
There’s more similar material in SN48.24, but that’s probably too much cut-and-paste already, and going off on a bit of a tangent.
There’s definitely a single internally coherent picture of concentration as a faculty running through the Indriya Samyutta (but doesn’t mean it sits coherently with the rest of the canon). IMO it’s one important data point to be considered in the question posed by the OP. It’s a pity though that the SN is just so inaccessible (a situation to be remedied within a few months thankfully).