They are always banged up (which is usually fine as they are the old guys anyways and Pops rests them) but this year even Leonard has been hurting and they have never needed to rest him until this season. I not saying this will be the year they drop off (everyone says that and loses the bet) but I think they are also just a good fit to play even if they are healthy.
I agree about Leonard, by not LMA: http://www.sportingcharts.com/nba/stats/individual-player-plus-minus-statistics/2015/ click team to sort by team. Plus/Minus per 36 Leonard: 10.5 Duncan: 11.6 Aldridge: 7.7 Aldridge has a lower +/- per 36 than every other Spurs rotation player. Among Rotation Players, he is 6th in RPM (7th overall).