If Legion!Len was pulled from the timeline before he decided to go get Mick
we're seeing the difference between Captain Cold deciding he needs a partner, going to him with a gift, asking for his company
and Legion!Leonard told he needs the Spear, going to Mick, to try and get something from him.
Very different attitude, very different results.
If you add in that a probable reason for the breakup was Mick getting distracted by the fire and Len not wanting to burn with him? Maybe he left because he thought Mick was dangerous, would mean he burns eventually, and the Legion told him he was right...
we're seeing the difference between Captain Cold deciding he needs a partner, going to him with a gift, asking for his company
and Legion!Leonard told he needs the Spear, going to Mick, to try and get something from him.
Very different attitude, very different results.
If you add in that a probable reason for the breakup was Mick getting distracted by the fire and Len not wanting to burn with him? Maybe he left because he thought Mick was dangerous, would mean he burns eventually, and the Legion told him he was right...