Andy Reid has been coaching for a long time.
Here is how the RB rushing attempts and targets have been distributed to RB players with Reid
1999 Duce Staley 325 rushing attempts 66 targets 41 receptions next RB 12 rushing attempts
2000 Duce Staley 79 rushing attempts 33 targets 24 receptions (5 games) Darnell Autry 112ra 37tgt 24 rec Brian Mitchell 25ra 21tgt 13rec
2001 Duce Staley 166 rushing attempts 91 targets 63 receptions Corell Buckhalter 129ra 21tgt 13rec
2002 Duce Staley 269 rushing attempts 69 targets 51 receptions Dorsey Levens 75ra 28tgt 19rec Brian Westbrook 46ra 13tgt 9rec
2003 Duce Staley 96 rushing attempts 47 targets 36 receptions (starts 4 games 28 years old) Correl Buckhalter 126ra 14tgt 10rec (starts 5 games) Brian Westbrook 117ra 48tgt 37rec (starts 8 games)
2004 Brian Westbrook 177 rushing attempts 87 targets 73 receptions (13 games) Dorsey Levens 94ra 14tgt 9rec
2005 Brian Westbrook 156 rushing attempts 96 targets 61 receptions (12 games) Ryan Moats 55ra 6tgt 4rec (7 games 1 start) Lamar Gordon 54ra (4 starts) 17tgt 11rec
2006 Brian Westbrook 240 rushing attempts 105 targets 77 receptions (15 games) Correll Buckhalter 83ra 28tgt 24rec (1 start)
2007 Brian Westbrook 278 rushing attempts 118 targets 90 receptions (15 games 28 years old) Correll Buckhalter 62ra 21tgt 12rec
2008 Brian Westbrook 233 rushing attempts 74 targets 54 receptions (14 games 29 years old) Correll Buckhalter 76ra 32tgt 25rec
2009 Brian Westbrook 61 rushing attempts 34 targets 25 receptions (8 games 30 years old) LeSean McCoy 155ra 55tgt 40rec (4 starts) Leonard Weaver 70ra 26tgt 15rec (8 starts)
2010 LeSean McCoy 207 rushing attemts 91 targets 78 receptions (15 games) Four other RB who get 40 or less opportunities
2011 LeSean McCoy 273 rushing attempts 69 targets 48 receptions (15 games) Ronnie Brown 42ra 2tgt Dion Lewis 23ra 1tgt 1rec
2012 LeSean McCoy 200 rushing attempts 67 targets 54 receptions (12 games) Bryce Brown 115ra 19tgt 13rec Dion Lewis 13ra 2tgt 2rec
2013 Jamaal Charles 259 rushing attempts 104 targets 70 receptions (15 games) Knile Davis 70ra 15tgt 11rec
2014 Jamaal Charles 206 rushing attempts 59 targets 4 receptions (15 games 28 years old) Knile Davis 134ra 25tgt 16rec
2015 Charcandrick West 160 rushing attempts 34 targets 20 receptions (15 games 9 starts) Spencer Ware 72ra 6tgt 6 rec Jamaal Charles 71ra 29tgt 21rec (5 games)
2016 Spencer Ware 214 rushing attempts 42 targets 33 receptions (14 games 14 starts) Charcandrick West 88ra 43tgt 28rec(15 games 2 starts)
While there have been some years where RB time share, for the most part Reid has a featured RB who is involved in the passing game a lot, unless that player gets injured. There is also a pretty strong trend of sticking with his starter as long as they are playing well enough.
There is some overlap of featured RB being drafted when the starter turns 28 years or older, from Staley to Westbrook (who only had 46 rushing attempts in his rookie year 2002) then Westbrook to McCoy happening sooner due to Westbrook being injured McCoy being very good.
Spencer Ware outplayed Charcandrick West and was their primary RB last season, looking at the history of this I think Reid shows a preference for a style of RB like Westbrook, McCoy, Lewis, Charles, West.
Spencer Ware may be more similar to Duce Staley, Buckhalter, Dorsey Levens, Ronnie Brown,Knile Davis. Ware is the incumbent starter however and Reid hasn't rushed his rookie RB into the lineup their first year unless there was an injury to the starter.
The starting RB for Reid averages 76 targets/season over this time frame (with some pro rating for missed games)