Both examples seem to overuse “more”,particularly given that they’re opening sentences where an precedent has already been set for susceptibility to- or a quantity of problems. In addition ‘Relentlessly’ seems to carry some subjective weight.

Will ‘thoroughly’ have fewer negative connotations?

I’d suggest’Children are susceptible to creating problems and endangering themselves and should be thoroughly supervised by parents ‘.

In regards to the wording of my question, it’s easy to misinterpret your answer.

Document A is, literally, the document. Document B is the reference. Document A

is “the source”. Document C is “a reference”.