That is not a valid reason. There is no law , rule or regulation that requires a full vote in the house to issue subpoenas. Pure nonsense.
The president doesn't get to decide how the House conducts investigations or impeachment.
Yes there is, turd. I have already quoted it
Contempt of Congress - Wikipedia
As announced in Wilkinson v. United States,[9] a Congressional committee must meet three requirements for its subpoenas to be "legally sufficient." First, the committee's investigation of the broad subject area must be authorized by its chamber;
That is not a law, dope.
From your link:
"Congressional rules empower all its standing committees with the authority to compel witnesses to produce testimony and documents for subjects under its jurisdiction. Committee rules may provide for the full committee to issue a
subpoena, or permit subcommittees or the chairman (acting alone or with the ranking member) to issue subpoenas."
Who's the dope?
Is the constitution not the supreme law of the land, dope.
There's precedent and under our legal system based on English common law, precedent carries weight under the law.
This ain't France, shitforbrains. And if you need to ask about that, don't you'll just look all the more stupid.