Here is Wallace on the definition of a clause.
Note the ESV:
1 Ti 2:5 For there is one God, and there is one mediator between God and men, the man Christ Jesus, 6 who gave himself as a ransom for all,
This is a paratactic structure.
"For there is one God" is a clause.
"there is one mediator between God and men" is a clause.
You said:
the verb, implicit as it is, is applied to the whole of the clause/thought
You don't understand what a clause is.
"the man Christ Jesus, 6 who gave himself as a ransom for all" has its own aorist verb that is rendered into past tense in English. If there were one verb for everything up to this point that would be it. But each clause has its own verb and "there was one God" is ridiculous.