There is no rule, but if you are not sure record in different tracks!
Personally if I use more than one mic for one take, I do in this way so in the mix I can balance them better if I need.
One of the reason of using more than one mic is to have different flavors, for example a clearer and a darker sound so in the mix time if you need the clear one more, it's enough to raise the level of that one!
Pay attention to phase issue and assure that the distance between the two mics and the speaker is the same (if you want to record the ambient is another thing!!).
Record also the line if you can in case of reamp!
Then reapeat for other 3 takes