Again, this is a pointless comparison.
Garcia was 26 when he joined us - in his prime, and from one of the best teams in the world.
Coutinho joined us as a 20 year old kid, and is still mostly a kid.
They're also completely different players - Garcia was a floaty goalscoring attacking midfielder. He had two great feet, a very good leap and a knack of scoring important goals. Technically, his touch was great, but he was no dribbler at all. He couldn't carry the ball 5 yards without tripping over himself in indecision, or backheeling it to an opponent or flicking it out of touch. His passing was extremely extremely inconsistent, and though he could play a good through ball on occasion, he was no playmaker.
Coutinho is a very different player. He's been bred as a playmaker. His control, touch and vision are out of this world - you're talking Zidane or Iniesta level. He sees and can make passes that Garcia wouldn't ever have made. Also, when he's fully focused, his ability to keep possession is outstanding. If football were a 5-a-side game, Coutinho would be one of the first players in the world I'd want in my team. Garcia would be one of the last - he'd flick the ball to the opposition every 2 mins. Coutinho's problems are two fold - his lack of intensity over 90 mins, and his lack of end product. If he fixes those, then by 26, he'll be a player miles ahead of Garcia.
Whether he does that is another question of course. I think the end product business can be remedied - there've been some encouraging signs regarding his shooting in the past few games. The real problem is his lack of intensity at times - his ability to last 90 mins, and his desire to boss the game on every possession is holding him back. I don't know what it'll take to fix that. If he does, he could easily be a top 10 player in the world. If he doesn't, I'm sure we'll continue to see more Garcia comparisons.
