If you only want one version, Classical Theravada is consistent which is to trust the commentaries. Of course, by seeing the inconsistency between some commentaries and suttas, out comes the EBT movement.
When we go to EBT, there’s ambiguity introduced because different people might regard different suttas as earlier or later, and even amongst those considered as early, some may, due to seeing no strong parallel support, regard some suttas in MN as late. The doctrinal stance can be different enough that there are groups of EBT teachers to support either side of the Jhana debate and either side of the parinibbana debate.
One way is to just place trust only in this EBT teacher, and you can ignore the rest. Then you’ll have to be familiar with the ins and outs of why this teacher believes this sutta to be early and so on, etc.
So I will roughly answer based on what I had learned.
Due to the nature of oral transmission, there can be stock phrases and repetition to make it easier to memorise orally. So possible that some things are simplified and standardised, like a lot of kids are just seven years old, 500 monks, the same stock formula for Jhanas. Does it mean the suttas are unreliable? No. This standardisation doesn’t change the essence of the Dhamma. It’s not that the teaching of the Buddha becomes false if you one day can time travel back and count 534 monks accompanying the Buddha to go here or there. Or that the Buddha uses different ways of speaking, but the meaning is the same for the Jhanas.
One can also just choose to believe that, indeed, repetition is a good way to teach orally in the first place, that the Buddha can speak in such a way first time already suitable for chanting and memorisation. And that, for different audiences for different talks, he can be consistent in using the same formulas for the Jhanas, for it’s new to this particular audience and so on…
Does it matter either way in terms of practice? No. The practice is the same either way.
By seeing the parallels and considering that there are no earlier versions, and that the scriptures and living traditions still produce results, just mix with Pa Auk lay groups, you’ll hear lots of things; it’s pretty certain that the true Dhamma is still in the world.
Really, what else is there to compete with the Nikayas to claim that the nikayas are not the words of the Buddha?
Ok, I see you have Mahayana background, and Mahayana affirms the Agamas. And agamas are mostly very compatible with the nikayas. Just see that the view of parinibbana not being total cessation that some mahayana texts would imply means that their dhamma is contaminated.
There’s also sources for how Mahayana ideas developed over time. The more one reads the Nikayas and compare with some Mahayana ideas, the more clear one sees where are the differences, and why later developed teachings in order to legitimize themselves, cannot say earlier teachings trumps the later developed ones, but they will have to resort to later teachings to explain away any possible inconsistencies.
Earlier is closer to truth is a taken for granted assumption we are working with here.
Does it matter to the practice if a certain rule is formulated here or there? Or that a certain samanera is 7 or 8 years old?
I think the Buddha meant for his teachings to be as pure as possible, but what are the options you’re talking about? The profileration of options from Classical Theravada to EBT?
If in doubt, I would tend to side with classical Theravada on the positions of Jhanas and Nibbanas. That’s a safe bet. Indeed, the Dhamma is meant to be reflected.
Just understanding Parinibbana is total cessation of all existence, of everything, you can see the flaws in many Mahayana teachings already.
How about you read the 4 nikayas first, then you judge? I think he is clear enough, but how later people distort the teachings can be questionable. Maybe some areas he is vague on purpose, but then that’s the value of commentaries.