Because of that, at this point, they should do it.
I am thinking this is ok, but is this ok?
Because of that, at this point they should do it.
I see people do it often, but I think it's just a grammar error, so I am wondering if there's any rule that says it's ok since there's already "because of that" with a comma.
Because of that, at this point, they should do it.
The above example is fine. at this point could be treated as an interruption and could hence be separated by a comma pair.
Because of that, at this point they should do it.
Because of that and at this point are introductory prepositional phrases.
Please refer to Englishplus for the following example.
Correct: Over hill, over dale, we hit the dusty trail. (The two phrases are in series here. We could say "Over hill and over dale.")
Our two phrases are considered parallel and hence should be separated by a comma.
Similar to cases where we place a comma after the last introductory phrase, we should have a comma here after at this point.
Because of that, at this point, they should do it.
By adding an and between the two phrases, we could show that Because of that and at this point are parallel.
Because of that and at this point, they should do it.
I believe we could test also by swapping the positions of the two phrases.
At this point, because of that, they should do it.
The sentence is still fine.
That first example is what's called a "comma splice"
See the heading "comma splice" here: https://www.grammarly.com/blog/comma/
The second example you wrote is better but to my native American eyes it seems awkward.
Good question.
