'Hockey age' isn't a thing. Unless you can provide some evidence that it's players GP that correlates to a player's performance and not chronological age?
You are not correct at all. There have been numerous articles written on the longevity of the butterfly goalies, both from medicine/doctor perspective as well as player management perspective.
It has been thought that there is only so much mileage the hips of goalie can take, one of the reasons for Brodeur's longevity was he didn't play that style.
If you google the topic there is tons of information.
This is pretty interesting:
Unuited States Library of Medicine -
http://www.ncbi.nlm.nih.gov/pubmed/25498869
PURPOSE:
This study aimed to characterize the radiographic deformity observed in a consecutive series of butterfly goalies with symptomatic mechanical hip pain and to use computer-based software analysis to identify the location of impingement and terminal range of motion. We also compared these analyses to a matched group of positional hockey players with symptomatic femoroacetabular impingement (FAI).
METHODS:
A consecutive series of 68 hips in 44 butterfly-style hockey goalies and a matched group of 34 hips in 26 positional hockey players who underwent arthroscopic correction for symptomatic FAI were retrospectively analyzed. Each patient underwent preoperative anteroposterior (AP) and modified Dunn lateral radiographs and computed tomography (CT) of the affected hips. Common FAI measurements were assessed on plain radiographs. Patient-specific, CT-based 3-dimensional (3D) models of the hip joint were developed, and the femoral version, alpha angles at each radial clock face position, and femoral head coverage were calculated. Maximum hip flexion, abduction, internal rotation in 90° flexion (IRF), flexion/adduction/internal rotation (FADIR), and butterfly position were determined, and the areas of bony collision were defined.
RESULTS:
Butterfly goalies had an elevated mean alpha angle on both AP (61.3°) and lateral radiographs (63.4°) and a diminished beta angle (26.0°). The mean lateral center-edge angle (LCEA) measured 27.3° and acetabular inclination was 6.1°. A crossover sign was present in 59% of the hips. The maximum alpha angle on the radial reformatted computed tomographic scan was significantly higher among the butterfly goalies (80.9° v 68.6°; P < .0001) and was located in a more lateral position (1:00 o'clock v. 1:45 o'clock; P < .0001) compared with positional players.
CONCLUSIONS:
Symptomatic butterfly hockey goalies have a high prevalence of FAI, characterized by a unique femoral cam-type deformity and noted by an elevated alpha angle and loss of offset, which is greater in magnitude and more lateral when compared with that in positional hockey players. Associated acetabular dysplasia is also common among hockey goalies.
LEVEL OF EVIDENCE:
Level IV, prognostic case series.
But tons and tons of info has been written on the subject
http://www.si.com/more-sports/2009/03/18/butterfly-hipinjuries
http://ingoalmag.com/news/butterfly-and-hip-injuries-backstrom-back-to-surgeon/