Now for the thigh armor.
The red part will be ID 3 and the remainder will be ID 2.
With the UVs corrected the result is in the viewport with smoothing.
The knee protection with the red ID 3 and the remainder in ID 2. For materials, a planar map for each one.
The UV adjusted and smoothed object.
Side protection with the ID 3 in red and the remainder in ID 2. There are two planar maps.
To the top left UVs as crude parts and on the top right after adjustments.
To the right with the part smoothed.
The large piece of the bust armor.
To the red faces apply ID 3 and the remainder ID 2.
Select the faces with the ID 2 (select by ID) and apply a Spherical Map. The use of such mapping seems curious but it is this type of mapping that will give us fewer final adjustments.
For the neck, use a Cylindrical Map.
(It is far more effective on this part).
Hide the faces with ID 2.
The left picture shows, the faces of Shoulder Protection selected. Apply a Cylindrical Map to this selection with the seam facing down.
For the decoration on the chest, apply a Planer Map.