Answer is always: it depends.
Pathing should be determined based on your opposing jungler, which side you start on and the laners champs for gank priority or kill potential. Graves is a great champ to know really well since he's so adaptable to fight early or power farm so there isnt always a set best way
Bot side start gives you higher ganking and fighting power since red buff adds more damage and CC which lets you contest scuttle easier than if you had blue buff open, and ideally would want to gank/fight with red buff up rather than powerfarm and have it wear off by the time you gank. IDK how you propose gromp-blue-scuttle into their red if you're top side and they leashed to open on their red, and there should never be a situation where you can do that path plus scuttle while the other jungler is still on the opening bottom side with red leash
Graves can end with a full 8 stacks when you contest for top scuttle too. Open with E to get 2 true grit stacks off the first buff, 2 more stacks at the next camp then cross your midlane by using E again when the stacks are about to all fall off so you can refresh it then will reach the cross quadrant raptors or wolves in time to auto and keep those stacks up. Buff 2 after that then by the top scuttle you'll have 8 stacks and full HP if you did it right. No one can fight Graves with full 8 stacks of true grit up (+40 armor) at level 3 which should leave the top scuttle uncontested. If the other jungler went buff, camp scuttle on bottom they wont have the time to clear top scuttle which keeps you even on scuttle count. If they for some reason went scuttle to scuttle just to get them theyd have to cross mid and youd know, and you can then invade them in their jungle as level 3 vs their 2.