Hi Morgana,
My reaction to your thoughts are, in order:
1) You're probably right.
2) But there wouldn't be much of a story in that...
3) Unless Trask killed Tempus before (subjective time) Tempus had ever interacted with L&C. If Tempus never met them, then the timeline might well have unfolded differently. Perhaps there might not even be a Utopia. (Now *that* would be ironic -- If Tempus were instrumental in the creation of Utopia!) Of course -- added irony -- Wells would have to enlist L&C to go back in time to prevent Trask from killing Tempus.
Now I think we have the makings of an interesting story here...
Joy,
Lynn