Slitherine

is there any way to change Hero allotment other than the start of a new campaign? when u import, how does that affect Hero allotment? once you start a new DLC, is the Hero allotted before every new battle already determined? is there anyway to preview the Hero path?

At the start of each campaign, a random seed is saved that controls what Heroes you receive.
Importing your army does not affect this process.

If you save your 'Turn 0' state, when you load your saved game you get the heroes.

If you enter 'runany Victory 0' in the Chat Window the scenario will end in a Victory.
You can then proceed to the next scenario and see what hero you get.
You can pick only 'Killer Team' trait to see which heroes you get, If you like them then use the 'Restart Scenario' Option to pick all the traits you want to use.

Scenarios started in Colonel and General get different heroes.
So if you save your last turn, just before Victory, you can try both levels to see which hero you like best.
The Victory Screen has the 'Change Difficulty' Button.