Good idea, Borat. What you are saying sounds like the sorts of scoring systems used in the various fantasy footy games which are around the place.
To start with, I'll use the system from the AFL fantasy football competition that I have run for the last 8 years, which although simple, we think works quite well. The only problem is that defenders are always undervalued.
Kicks: 2 points
Handballs: 1 point
Marks: 3 points
Goals: 4 points
Tackles 2 points
Hit Outs: 1 point
Under this system (which you may or may not think is fair...) the reserves player averages are:
(games, name, average)
1 Knights, Chris 92.0
5 Gibbs, Bryce 73.8
5 Reavill, Matthew 72.2
9 Horan, Jack 65.1
4 Cook, Sudjai 65.0
15 Willits, Ryan 59.5
14 Block, Lucas 59.2
18 Ruwoldt, Mark 56.5
1 Salopek, Steven 56.0
2 Kirk, Daniel 55.5
12 Greenwood, Malcolm 55.4
18 Allen, Ty 54.3
3 Stephens, Brad 54.0
18 Doswell, Brett 51.3
8 Andrews, Rowan 50.6
10 Burdett, Marcus 50.2
1 Bradshaw, Shane 49.0
15 Hinge, John 47.7
5 Schuback, Jacob 47.2
8 Statham, Craig 47.1
1 Holmes, Tom 47.0
7 Panozzo, Luke 46.9
10 Herbert, Lucas 46.6
19 Reavill, Daniel 46.2
1 Cranston, Trevor 46.0
2 Rogers, Aaron 46.0
11 Yeomans, Bradley 45.3
10 Allison, Paul 43.2
9 Krueger, Josh 42.8
9 Gamble, Ryan 42.6
19 Lally, Angus 42.3
7 Smith, Jeff 41.0
12 Griffiths, Michael 41.0
14 Bradley, Will 37.3
23 Button, Alex 36.4
17 Milne, Jeremy 36.0
10 Bell, Brad 34.6
2 Dixon, James 33.0
11 Dubieniecki, Clinton 31.5
12 Joraslafsky, Matthew 31.3
10 Redden, Thomas 30.4
3 Graham, Matthew 28.7
6 Sugars, Brad 27.3
11 Cooper, Tom 25.0
8 Longman, Daniel 24.3
12 Kaesler, Barry 24.2
1 Stone, Will 24.0
18 Bennett, Phil 23.6
1 Sellar, James 20.0
23 Wade, Ben 19.4
3 Kellock, Jarrod 18.3
5 Cantwell, Sean 16.4
1 Voigt, Ben 11.0
2 Wood, Jakob 9.5
1 Bailey, Tom 9.0
PS TB won't be happy with Ben Wade down the bottom, but I don't think any statistical system can accurately determine the true value of a full back