Specific techniques and disciplines originate in light of a specific context.
The context: Wet surfaces
The technique: Keep the hands dry
The exhibited ‘fingertip technique’ of stealth movement is meant to keep the palms of the hands dry when coming into contact with wet surfaces. This allows the stealth operative to readily grab on to other surfaces without having to worry much about slippage or a bad grip.
To strengthen the fingers for stealth climbing, crouching, and hanging, fingertip push-ups and body-weight hand-plants will have you on your way.
With enough practice, you will gain ‘Hands of Stealth’.