Girona has been great in the last two seasons. But when it comes to trophies I agree with what you have said that it is still quite difficult for Girona. What differentiates Girona from Madrid or Barca is that both teams have quite good squad depth. Playing a fairly busy match between La Liga and the Champions League certainly requires consistency in the game. And if the reserve players are not as good as the main players, it will be a problem if some of the main players are injured. So apart from good performance, consistency is also needed to become a champion.
Girona's quality may only be good for La Liga and to measure how well they can manage their busy competition schedule they will have to try to get a place in the champions league next season. I agree that every team must have reserve players who are as good as the main players and that is what Real Madrid and Barcelona currently have, so however, Girona, with the depth of their current squad, I don't think can match these two teams in the title race. Being able to finish in the top 4 is a very realistic thing for them.
At some point, I won’t have much confidence in them to even finish on the top four spot in the league. But as it is now, they look so serious and want to keep dominating their position in the top four of the standings. It is true that Girona does not have a very good squad depth to keep themself at the top of the race but I feel they can still manage when playing in just one competition. If they eventually secure a place in the champions league competition by next season, they can add to their squad and make it more stronger so that they can compete well in both competitions at that time. At this point in time now, they need to be focused and not lose hope despite the competitive pressure that will be on them now with their current place on the La Liga standings.
Girona has proven to be a serious title contender this season in La Liga, they came from behind to beat Valencia in the dying minutes of their match, and if not for an offside their match with Valencia could have ended 3-1 in favor of Girona. Even though Girona does not win the La Liga trophy this season, they will book a spot for next year's Uefa Champions League.