1st, no Jew died during the days of darkness, the darkness occured only among the Egyptians (see vs.Ex.10:23)
2nd. The Jews are said to have come out in armies in Ex. 12:51).
Thus, Ex.13:18 tells us that they came out 'harnessed',(by fives) in other words, by ranks.
So, in the beginning of your comment you state that the Hebrew can only mean 'armed' but then state that it can also mean 'divided by five'.
That is how the KJB translated it, hence the word 'harnessed'.
Other modern versions have 'orderly ranks' (NKJ) or 'martial array'(NAU).
The point being they left in order not as a mob.
I’m quoting Rashi.
The topic answered the question of a photo caption indicating Jews came out of Egypt armed.
Someone asked for the Biblical reference.
I responded, noting it was a Jewish translation at variance with the KJV.
I realize Jew-hating idol-worshippers have alternative views of straightforward Jewish texts.