I wont insert this meaning (the meaning from this quote of yours') into the canon, as it appears you have. It is clear (by the writings of Saint Basil the Great etc) that there is a distinctions with regards to the different heretics -- heretics of the second rank, as repeated here, have an empty form, and if they repent of the heresies, that cause them to be accounted a heretic of the second rank, they can be received, God willing, in the rank they hold, and at that point receive Grace. You might be tempted to "reason" that this is a form of Grace, but, this is incorrect thinking, on account that the saints staunchly declare that they, the heretics of the second rank, have no Grace.
On a side note: it appears to me, that your use of laymen, is wanting.
St. Basil's first canon clearly states that the clergy of heretics and schismatics are laymen. In this regard, he does not distinguish between different "ranks" of heretics. So I guess your answer to my question is B
St. Basil's opinion is that all schismatics and heretics should be rebaptized, reordained, etc. The only reason he allows for reception by chrismation for some groups is that some of his brother bishops have already allowed this, and he doesn't want to gainsay their decisions or imperil anyone's salvation. So St. Basil's perspective was already not universally accepted by other bishops. Which leads to a very important point about St. Basil, St. Cyprian, and other Fathers who spoke on this question: They were speaking as
bishops of a Church that had
bishops, bishops who had the authority to apply or relax canons as they saw was needed, and who were receiving people from peripheral sects- not pinning the existence of their communion on this reception. This is completely different from the situation of the Old Ritualists, who depended entirely on those they deemed "heretics" for their priests, bishops, and apostolic succession.
So, you can talk as much as you like about filling "empty forms" with grace, but the fact remains that, according to your own reasoning, and the very canons you cite for your support, you must regard Ambrose as having been a layman. Therefore, your church's line of bishops derives from laymen who had the "empty form" of episcopal orders. So I might turn your own question back at you: Where is the canon that allows laymen to not only consecrate bishops, but create a whole line of episcopal succession?
Met. Ambrose obviously saw the absurdity of his situation in some sense- hence he tries to say that it is really the ancient Patriarch who is receiving him, and not the priest, because he knows that a mere priest does not have the authority to receive him as a bishop. And then, as a newly minted bishop, he forbids priests to anoint bishops, even though that is just what happened...
Lastly, this talk of filling "empty forms" of baptism or ordination is of fairly recent vintage- I doubt you can locate it before the 20th century- and it originated from "new ritualists" such as St. Justin Popovich who were trying the reconcile the teaching of St. Cyprian with the church's practice of receiving Roman Catholics, Lutherans, etc. by chrismation or even mere confession of faith. So not only are you entirely dependent on us for your orders, but for your ecclesiology as well.