I have to say I don't think he's much like Adebayor at all.
I've watched Isak fairly closely since he was 15 and I feel pretty confident that he's going to be world class one day. Everyone knew it right away with Zlatan and everyone who saw Isak break through knew it with him too. They both had more in their mid-teens than most players acquire across a full career.
It's a lazy comparison usually because it's mostly based on nationality when people make it, but he really is similar to Ibrahimovic. I can't really think of any other striker I've seen who has been so similar to Zlatan's unique style, creator and goalscorer in equal parts, and a mean dribbler for good measure. Their technique is insane for such big lads. When Isak bulks up in a few years there won't be a defender in the world who can stop him.
That being said, you just need to watch him a few times for Sweden or Real Sociedad to see that he's still on a learning curve. He's a patchy goalscorer and a little too lethargic on the ball for my liking. If we actually sign him we're likely going to have to wait for a few years before he's starting quality for a club like Arsenal. That's not really an argument against signing him, it's just something to keep in mind. He'll also need a good attackminded manager, and I find Arteta shockingly lacking in that respect. A bloke who manages to coach Aubameyang down to ten league goals and spends every waking moment buying more centrebacks is not going to work wonders with any young strikers we bring in.