All together and With the benefit of hindsight

All together adverb - Used of a group whose members acted or were acted upon collectively and when `all' and `together' can be separated by other words.

With the benefit of hindsight and all together are semantically related. In some cases you can use "With the benefit of hindsight" instead an adjective phrase "All together".

All together and with the benefit of hindsight are semantically related. You can use "All together" instead an adjective phrase "With the benefit of hindsight".