I’m not really sure why you care to defend this–since, to put my response in the same manner as yours:
Does the tenth amendment have anything to do with enumerating rights?
A: Yes, through some unclear mechanism.
B: No, article V defines how you amend the constitution to enumerate rights.
That’s a simple, textual contention. The fact that a power is, in part, allocated to state legislatures has nothing to do with whether that allocation is pursuant to the tenth amendment or some other constitutional provision. Further, state legislatures and congress are not “the states, or the people.” So, to put it mildly, the tenth has nothing to do with amending the constitution.
Your question is rhetorical, but to go ahead anyway,
And which of those three amends the constitution? A: false disjunction. None of the above amends the constitution individually–it is not, as you imply, “the states, or the people.”
In this case, we don’t need to do anything more than read the plain text of the constitution to prove you wrong–an argument I’m sure you’ll appreciate.
Regardless of whether the amendment is by convention or by submission to the states, congress is necessary. Plain text of article V. That, on its own, is enough to take the tenth out of the picture–since the power is, in part, allocated to an arm of the federal government.
And the power isn’t allocated to “the states, or the people”–it is, in part, allocated to state legislatures. Different than the Tenth.