What does Thin Red Line do in AoE3?

Musketeer: hit points +20%, speed −10%. The game says: "British Musketeer hitpoints increased but march more slowly."

Technology

Thin Red Line

Thin Red Line (tech ID ChurchThinRedLine) is a technology in AoE3: Definitive Edition 100.19.18309, 15 s to research at the Church and Shrine. Effect: Musketeer: hit points +20%, speed −10%.

Quick answers (2)

What does Thin Red Line do in AoE3?: Musketeer: hit points +20%, speed −10%. The game says: "British Musketeer hitpoints increased but march more slowly."
What is the tech ID of Thin Red Line?: ChurchThinRedLine.

British Musketeer hitpoints increased but march more slowly.

What it does

Musketeer: hit points +20%, speed −10%

Research time: 15 s
Game ID: ChurchThinRedLine

Researched at

Church

Shrine

Needs

The Glorious Revolution

Civilizations

Source: techtreey.xml and the Home City files, AoE3: DE 100.19.18309 (build 25040513).