Craig, it seems like it's hard to project what an extremely hard-working 21-year old athlete (as Triantos) might develop into as a hitter.
This is by no means a comparison to the GREAT Hall-of-Famer, Ryne Sandberg, but as a 21 y.o. in AAA, in 519 ABs Ryno hit 17 2B, 5 3B and 9 HRs. (he was called up to Phil. by end of year).
In 443 ABs this year, Triantos hit 23 2B, 6 3B and 7 HRs. (and stole 47 bags to Ryno's 32 in his 21 y.o. and last minor season).
As we all know, Ryno was taught by manager Jim Frey how to turn on pitches and pull the ball with more power. Can Triantos make some adjustment that will unlock 20+ HR power? Maybe. 21 y.o. is still awfully young for a pro hitter.
Ryno was taller (listed at 6'2, 180), whereas Triantos lists at 5'11, 195. (Alex Bregman is listed at 6'0, 180 and admits he's not 6' tall and, by the way, in A and A+ as a 21 y.o. in the minors, Bregman hit 4 HRs in 272 ABs...and a whole lot more since then)
Nico H. has similar dimensions to Triantos and hasn't yet unlocked more power. Maybe Triantos won't, but maybe he will make an adjustment that unlocks more power or add a few feet of carry as he grows into his fully-developed man muscles.
I do hope Cubs don't let him go based on the assumption that he will never hit for power! As he's becoming a plus fielder at 2B, Triantos sure looks like he has MAJOR upside to me.