Isabella, taken in the second round of April's NFL draft, stands at 5-foot-9. Butler, taken in the fourth round, is 6-foot-5. Where they stand on common ground, though, is that both were overlooked coming out of high school, with Isabella going to UMass and Butler going to Iowa State.
But they'll both be given an opportunity to make an immediate impact in the NFL in coach Kliff Kingsbury's Air Raid scheme.
And that means both can be fantasy diamonds in the rough.
So, what kind of duo can they be?
"We're going to figure it out," Butler said. "It's going to be dangerous, though."
ESPN NFL analyst Matt Bowen, who also hosts NFL Matchup, expects the foundation of Kingsbury's offense in Arizona to be the core Air Raid concepts, many of which are standard in passing offenses throughout the league: "You see four verticals, you see three-level flood routes, you see that Y-cross where you occupy or you put defenders in conflict and drag that guy across the field to an open window. You're going to see all curls, you're going to see all slants, you're going to see post wheel.
"A lot of the same things he ran at Texas Tech -- it might just be dressed up a little differently."
Bowen, who played defensive back in the NFL for seven seasons, also believes Kingsbury will move the pocket often for two reasons: He has a dynamic dual-threat quarterback in Kyler Murray, and the Cardinals' offensive line is still a liability.
And Isabella and Butler each has a unique skill set that could help him find a productive role in the offense.
Because of his size, Isabella will be pegged as a slot receiver in the NFL, Bowen predicted, but Isabella has experience running a vertical route tree, and he can also run intermediate cuts such as crossers and square ends, screens, shallow crossers and square end cuts.
"If you're talking about using him from a slot alignment, run him up the seam and from an outside alignment, the deep post, run the deep quarter route because his speed is legit and his ability to separate from coverage is going to give Kyler more of an open window to throw," Bowen said.
Beyond Isabella's route tree, Bowen said the receiver's ability to run after the catch could make him an instant factor for Arizona.
Butler's size can help him have the same affect, Bowen said.
His ability to play inside and outside, coupled with his size and speed, can make him a matchup nightmare, Bowen said. If he's facing a safety inside, then Murray can call a seam route for Butler, Bowen said. Bowen also believes Butler can be a factor in the red zone, on third downs and in plus-20-yard-line situations where Butler can use his size to win contested throws.
"You're going to have to put the ball up high, let him go climb the ladder and try to make a play for your quarterback,” Bowen said. "He did that a lot at Iowa State."
Both players used their own distinct style to catch more than 1,000 yards last season. Isabella turned his 4.3-second speed in the 40-yard dash into 1,698 yards and 13 touchdowns while playing inside and outside. Butler used his size and speed -- he said his fastest 40 time in the draft process was a 4.35 -- to haul in 1,318 yards and nine touchdowns while playing all, he estimated, but three snaps inside.
After getting drafted, both Isabella and Butler immediately studied Kingsbury's offense at Texas Tech to get an idea of what they'll be running in the NFL.
Isabella got the sense he'd be used more as a slot receiver, but he also knows that Kingsbury would "run a lot of receivers" in college. Kingsbury said Isabella's versatility playing inside and out was "exciting to us." Kingsbury also noted Isabella's ability to create separation and space on the outside.
"He's dangerous on the inside, as well, but he's a guy who showed he could do it both on a high level," Kingsbury said.
Butler noticed from the film that Kingsbury usually had tall receivers who "made plays," a role he sees himself fitting.
"I've never tried to just put myself in a box where I'm like a one-trick pony, I guess," Butler said. "I'm excited about it. He sees what his players are good at, and he puts them in the right positions."