Activation Phase
The player with the initiative may either activate a model or cede the initiative to their opponent in which case they must activate a model.
Each player then alternates activating models. Each model performs a single action
to completion, and then the opposing player does the same.
If one player runs out of models, then the other player may continue activating units until all units have been activated.
When a composite model is activated, each part performs an action before that model’s activation is complete. The controlling player chooses the order this is done in, and each action must be fully resolved before moving onto the next part.