Size doesn't matter if you don't know how to properly use it. Jones knows how to use his reach to his advantage. That advantage was neutralized against Gustafson. I think in the rematch Jones will do a lot better since there's a lot of room for improvement on his end (I'm not a jones fan, just looking at it objectively).
As far as DC goes, I have to say I'm really impressed overall by DC. Not just does he have an incredible record, he's just a really good overall fighter with exceptional wrestling. His striking may not be as good as a pure striker, but as many people of have said before, it's not that important in mma. What is important is the fact that when facing a pure striker, they'll be so worried about the takedown, it'll reduce their striking skills. From what I've seen from DC's fights, he's so good at getting his opponent down, it opens up a whole world of options as far as take downs and striking goes.
In short, I don't think his striking is overrated at all. I think he's using his striking to their fullest potential at his current skill level and it's working out great for him!
He's only going to get better in the next couple of years.
1. Connor Mcgregor
2. Joanna jedrzejczyk
3. Anthony Pettis
4. Ronda Rousey