Action selector

Need	Prefer	Avoid
Persistent locomotion/mode	State Machine, Blend Space, Motion Matching	long looping Montage as primary locomotion
One-shot full-body action	Montage through full-body Slot	state explosion for every action
Upper-body action over locomotion	Montage Slot + Layered Blend per Bone	replacing the locomotion base
Start-loop-end action	Montage Sections with runtime next-section change	restarting separate assets every loop
Contextual animation variant, same timing contract	Child Montage or data-selected Montage	branching gameplay logic inside animation assets
GAS-owned ability action	Play Montage and Wait Ability Task	unmanaged montage lifecycle
Pure cosmetic one-frame response	short Montage or additive blend by complexity	authoritative gameplay in a cosmetic notify

Before authoring, write:

• who may start the action;
• when commitment begins;
• which inputs buffer or cancel it;
• whether locomotion continues underneath;
• who owns displacement/collision;
• which outcomes are completed, interrupted, or cancelled.

If those are undefined, additional Montage Sections will conceal rather than solve the design gap.