Where did you see an Ethier comp to DPete? 
Besides batting from opposite sides of the plate, Ethier produced 4 seasons with a WAR of ~3.5, a couple more ~2.5 WAR seasons, and a career .822 OPS.  
If DPete was projected to have that type of career he would be a FV 60-65 guy and would rank up there with Swanson and Albies.
		
		
	 
This was towards the bottom of the article:
Noteworthy Mahalanobis Comps for 40+ FV Prospects
Rank 	Prospect 	Most Noteworthy Comp
1 	Dansby Swanson 	Troy Tulowitzki
2 	Ozzie Albies 	Rickie Weeks
4 	Kolby Allard 	Carlos Carrasco
7 	Max Fried 	Tom Gorzelanny
8 	Luiz Gohara 	Javier Vazquez
9 	Mike Soroka 	Carlos Zambrano
10 	Cristian Pache 	Grady Sizemore
11 	Sean Newcomb 	Freddy Garcia
13 	Touki Toussaint 	Oliver Perez
14 	Patrick Weigel 	Daniel Cabrera
15 	Travis Demeritte 	Keith Ginter
17 	Ray-Patrick Didder 	Jason Conti
18 	Dustin Peterson 	Andre Ethier
22 	Derian Cruz 	Luis Ordaz
24 	Alex Jackson 	Eliezer Alfonzo
25 	Rio Ruiz 	Hank Blalock
26 	Dylan Moore 	Kevin Millar
28 	Austin Riley 	Matt Holliday
30 	Ricardo Sanchez 	Javier Vazquez
31 	Jonathan Morales 	Brandon Inge
32 	Randy Ventura 	Anthony Sanders