The underlying theme and motivating question of Analayo’s article seems to be the relationship between jhana and stream-entry. From the final part, it seems that his own belief is that jhana is not necessary for this. Most of the paper is an effort to weaken what I think he feels would be a very strong evidence point against this overall contention. I wouldn’t really call this a straw man. Maybe it’s just that Analayo himself believes this data point would otherwise seriously weaken his own conclusion and so feels the need to undermine this potential evidence. You make a good point on SA 784 and MA 31, though I think he still largely succeeds on weakening this data point. “Denying the antecedent” seems a stretch. I just think Analayo feels that other evidence against his viewpoint does not amount to much and cursorily dismisses it. I think you would very much take issue with that, of course! Likely Analayo should have looked at all that in his paper.
Samadhi and enlightment do involve levels and degrees, levels of enlightenment and degrees of samadhi. For example, in the SN, we have suttas ranking followers in degree of accomplishment the five faculties (including the faculty samadhi), starting from faith followers and Dhamma followers, going all the way up. I don’t think anyone is arguing that samma samadhi = jhana is not very largely true. The integral nature of jhana to the Buddha’s path is, I think, very very clear in the suttas. However, stream entry is at the margins of enlightenment. When something has levels 1, 2, 3, 4 etc. doesn’t necessarily mean 0.5 isn’t in the same category, e.g., take the four stages of enlightenment. If that was the only scheme, then we might say that anything before stream-entry was not enlightenment (doesn’t meet the minimum bar). However, then there is also the scheme of the 8 types of noble person in the suttas (path and fruit), and the person on the path to stream-entry (kind of at level 0.5 in the first scheme! 
). My point is things on the boundaries are not always so clear-cut and Analayo seems to be mostly looking at the fringes of the jhana and samma samadhi overlap here.
One thing I’d generally fault with Analayo’s reasoning is that he tends to be a bit too confident in his conclusions at times; I can think of examples where I’d both tend to agree and tend to disagree with his conclusions and where I still think the underlying evidence is a bit thin and he is being a bit too confident in his conclusions. I think there’s a lot to be said for, at times, just coming to the conclusion that something is just not clear from what evidence there is. Many things seem very clear in the suttas, but some things just seem not at all clear-cut (at least to me - though I’ve still a lot to learn ).
The relationship between jhana and stream-entry doesn’t seem very clear to me in the suttas. To expand further in terms of SN55.5, I’m sure SN55.5 is fulfilled at the moment of the opening of the Dhamma eye. Suppabuddha was mentioned earlier, which is one of the many descriptions of this happening when someone is listening to a discourse of the Buddha:
When the Buddha knew that Suppabuddha’s mind was ready, supple, without hindrances, elated, and confident, he revealed the teaching unique to the Buddhas: suffering, its origin, its cessation, and the path. Just as a clean cloth rid of stains would properly absorb dye, in that very seat the stainless, immaculate vision of the Dhamma in Suppabuddha: “Everything that has a beginning has an end.
However, what exactly is the relationship between this moment and jhana? This breakthrough to the Dhamma must be an absolutely extraordinary moment, lokuttara samādhi as you mentioned. Surely, this lokuttara samādhi must be samma samadhi and therefore SN55.5 is fulfilled and all factors of the path are present and now in the possession of the person (including samma samadhi).
However, my question then is whether this lokuttara samādhi is also jhana? This may not necessarily be the case. This lokuttara samādhi moment is extraordinary and so is jhana. Two extraordinary things, though, do not necessarily have to be the one and the same thing.
If this lokuttara samādhi moment is jhana, SN55.5 is fulfilled in a very simple and direct way, but are we sure that it is, though? If not, the relationship between jhana and this opening of the Dhamma eye is more complex and less straightforward.
Is the case, then, that there must have been prior or supporting experience of jhana for this breakthrough to the Dhamma to be possible? Is there sutta evidence for this? Passages like this above could have made this clearer if it this was the case. Absence of evidence isn’t evidence of absence, but still.
Or perhaps jhana immediately and inevitably follows this breakthrough? That would essentially fulfill SN55.5 also in another way. Of course, it will inevitably come later in the path, but does it necessarily follow straight after stream-entry?
A fourth possibility is that jhana may come later and that this lokuttara samādhi is when samma samadhi arrives and it is this ennobling of the disciple that may allow samadhi to subsequently be called “right” even maybe when it is not yet jhana.
I’m posing questions I don’t have answers to. They don’t seem clear-cut to me at this point.
Anyway, I really must read A Swift Pair of Messengers again and reexamine your holistic bigger picture Ven Nyanaponika- type treatment of these questions. I very much enjoyed it last time. Maybe I’ll come around to your viewpoint on this or maybe I won’t (or maybe I’ll sit on the fence 
)!
Anyway, I’m dragging the thread in an off-topic direction with this. I’m not sure what prompted me to head off in this direction in the first place, particularly when it’s not as if there isn’t reams upon reams of threads on this site on the topic already. Anyway, I’ll stop now!!
