*silly trumpet doot doots*
I'm baaaaaaaaaaaaaaaack! Freeeeeedom!
So since the Myranyn vs Harmysyn reforms are neck and neck at 31 each(at the time I started writing this) I am going to push very strongly for Myranyn.
First, the reason to take it. It is a massive blow against the Second Son crisis, either by outright ending it once the event chain is finished, or weakening it enough that the end conditions are less painful. This is achieved by using our obscene arming ability with the Ironworks and pushing out tons of basic crossbows. This is an Early Classical era development, which for us essentially puts all the ability of war on the state which doles out the food to the urban poor populations. This weakens the Yeomen for a couple of reasons:
They are hilariously outnumbered by the poor, who have easy to use weapons en masse and are incredibly loyal due to being fed.
Next no single patrician is in control of this food supply, our bureaucracy is far far to complex for that to make any kind of sense. More than that it makes much more sense that its the clerks who hold the real power since they can just not do their jobs and there ya go stuff starts locking up, and clerks are low patricians at worst.
Why would the Yeomen still have weapons provided to them by the government like they are being given now, when they are both the source of massive problems and there is a better option in the poor? Any self-respecting bureaucracy will go with the cheaper option of the poor. E: Though thinking about it the Myranyn reforms don't explicitly say that they take away their war fighting ability and instead still leave them some options to go through for advancement so it's more a shifting of the warrior ratio.
Next, about the long term problems brought about by the Marian reforms in our reality. To start I will state boldly that We are not Rome. Rome's downfall came when under the Marian reforms they had the idea to pay the army in either coin, or conquered land if coin was not possible(which happened because China if I recall correctly was sucking up obscene amounts of coinage). It was this second part, the land grabbing which expanded Rome until it burst, and we know how that story went.
Thus you can see the first big difference between the Ymaryn and Rome, we do not hand out land, we do not distribute. So long as we do that and don't reward successful generals with land on the frontier we will avoid that particular pitfall.
Also with our trade dominance we are more in a position to play China than Rome when it comes to amounts of shifting specie and coin, which means payment is a lot easier.
Will taking this have issues made possible that were not before? Absolutely, but those are ones we are pretty set up to deal with right now and we know exactly what they are, and they put the hurt on our current issues.