Is sufficient? ".. and all other churches..." Based on what? What studies have been prepared? Sounds like you just want to contradict.
I never disagree with people to be contrarian; I regard contrarianism as a great sin and would were it not for my catechesis yield to the temptation to resent the accusation and take offense, except I also regard harboring resentment as a great sin; it is better to exercise
apatheia. Besides, it is meet for an Orthodox to regard himself as the worst of sinners; I sincerely believe you are more pious than I am, even though you are in error concerning the reason why I disagree with you.
Rather, that reason is twofold: firstly, I reject your contention that our priests are incapable of determining on their own when someone is ready for baptism, and that there is a need to create specific programs depending on which church someone converts from beyond what we already have, which is defined by canon law and church policy. So it is already the case that Mormons, J/Ws and Seventh Day Adventists have to be baptized in most jurisdictions, as well as anyone not baptized according to the Trinitarian formula, as opposed to merely being chrismated.
Secondly, your view, aside from its lack of confidence in the priests, as I see it also suggests a lack of confidence in the transformative powers of the Sacred Mysteries of Baptism and Chrismation and Confession and the Eucharist. When we receive someone, they are sacramentally changed.
Here I shall also reiterate that Eastern Orthodox jurisdictions that actively evangelize conduct a formal catechumenate before receiving people. It is not as though a Mormon can just walk into an Orthodox church and be baptized on the same day. Additionally, the ban on neophytes being ordained, that is, people who have been Orthodox for less than three years, except for the very small number of clergy deemed worthy of reception by vesting, adds an extra layer of protection.
My point, therefore, is you should trust the bishops, trust the priests, and trust the Mysteries, to get the job done, as they have been doing. After all, it is not as though are churches are overrun by half-catechized conwertsy who have brought errors like acceptance of homosexuality and iconoclasm with them. Indeed the left wing in Orthodoxy consists largely of cradle Orthodox, both from the Old Country and the children of converts who made the mistake of sending them to public schools (although there are also left wing converts; I can think of one, but I am not sure I accurately recall his name, and I don’t want to accidentally libel someone).