They'd have less talent? Maybe only offensively at center, but did the Spurs really need an offensive oriented center who's value is tied to usage? No they did not. Plus, the position is getting more and more useless -- especially if the center is an immobile one that can't defend the PnR, which Gasol is. Smart teams like the Blazers are noticing this and stockpiling two way wings of quality that can still do some dirty work on the boards. That's what Harkless is, except Harkless can play the PF and guard 1-4 positions like Draymond ( no he's not on Draymonds level). Leonard and Green have needed and still need help on the perimeter, no one else on the entire roster is good enough on the perimeter to compete and defend against the best teams.
You're right, there was no answer for Golden State short term that the Spurs could have done in one off-season besides signing Durant. Once they lost out on him, the best they could have done ( imo) , long term, is start building a team that CAN beat them during Leonards prime. Instead they just prolonged that whole process by 2 years with the Gasol signing, and their inability to trade Parker. Now we may not see THE START of any progress towards a championship til 2018.
It is what it is. At the end of the day, I'll hope for the best, but I just think the team should have went a different route this past summer. No real progress will be made til 2 more years.