Mitchell Trubisky coming to the Giants makes so much sense for so many reasons — other than the small details that they probably cannot afford him and the rather large possibility that his presence on the roster could severely compromise Daniel Jones’ chances of ever living up to the expectations the franchise once had for him.

Yeah, it’s complicated.

The Giants are in the market for another quarterback, and the new regime — general manager Joe Schoen and head coach Brian Daboll — say they are committed to doing everything possible to help with Jones’ development — development that has stagnated since his promising 2019 rookie year. They also want to strengthen what has been a shabby backup quarterback position. The Giants have interest in Trubisky, but it might not go beyond that, as far as any sort of impending signing when free agency opens next week. There are financial and competition barriers for the Giants that likely lead to Trubisky signing elsewhere.

The Giants are aggressively trying to get under the salary cap — they were about $5 million over as of Wednesday — before next week’s deadline and will not have a great deal of money to spend in free agency in general and on a backup quarterback in particular. Trubisky is going to command a whole lot more than the minimum-wage deals the former Giants front office used to bring in Mike Glennon, Colt McCoy, Alex Tanney and Josh Johnson in recent years.

If it is Trubisky, this is not a clear-cut No. 1 and No. 2 situation, as there is a case to be made Trubisky, 27, is the better option and that signing him shows the new brain trust actually has very little faith that Jones, 24, can be the guy going forward.

That Schoen and Daboll — and also new quarterbacks coach Shea Tierney — know Trubisky from their one year together in Buffalo in 2021 makes this even more intriguing.

“I would sign a competent backup,’’ Chris Simms, the former NFL quarterback and current NBC Sports NFL analyst, told The Post. “To me, Trubisky would be the perfect guy as a backup.’’

Simms, the son of former Giants Super Bowl 21 MVP Phil Simms, then paused and reconsidered when it was suggested that Trubisky might actually be too good of a player to fit the description of “competent’’ backup.

“I hear you,’’ Simms said. “The money, too, I get that. They have to have somebody to cover their [butt] a little bit.’’

Jones missed the final six games of the 2021 season with a neck injury. It is expected the Giants will allow Jones to play out the final year of his contract, with the anticipation they will decline to pick up his fifth-year option of $22.3 million for 2023.

The Giants want to add someone to push and compete with Jones, but this is always a delicate balance. Does Trubisky get every opportunity to actually win the starting job? Daboll would have to be sensitive to the very real possibility that the first interception or fumble by Jones during the season prompts a “We want Mitchell’’ chant from the fans.

The new front office signed Davis Webb, the Giants’ 2017 third-round pick, based largely on the familiarity Daboll and Schoen gained the past three years with Webb on the Bills’ practice squad. Webb knows Daboll’s offensive system inside and out and should be a great resource to Jones for as long as Webb is on the roster. He is not a threat to supplant Jones, and he is not being viewed as the No. 2 quarterback.

Trubisky also knows Daboll’s system.

“I’m excited to see what he does in New York, really,” Trubisky said this week on Adam Schefter’s podcast. “I don’t know where I’m going to go, but I know whatever he does there, he’s going to do a great job with that offense. He’s a great leader of men. He’s just real and authentic with all the guys, and I think that is why so many people respected him in our building.’’

Trubisky will never be able to live up to his ridiculously lofty draft status — the Bears traded up into the No. 2-overall slot in 2017 to take him out of North Carolina. That the quarterback-desperate Bears passed on Patrick Mahomes (No. 10 to the Chiefs) and Deshaun Watson (No. 12 to the Texans) made Trubisky’s struggles even more incriminating.

Trubisky, though, put up numbers in his four years in Chicago that dwarf Jones’ three seasons with the Giants. Trubisky is 29-21 as a starter, with 64 touchdown passes, 38 interceptions and a career passer rating of 87.0. Jones is 12-25 as a starter, with 45 touchdown passes, 29 interceptions and a passer rating of 84.3. Trubisky has 14 lost fumbles, Jones has lost 28.

Trubisky spent the 2021 season sitting behind Josh Allen in Buffalo as a reset before hitting free agency next week.

“You know, nothing but positive about Mitch,’’ Bills general manager Brandon Beane said last week at the scouting combine. “He’s just a marry-your-daughter type of guy. For his ups and downs in Chicago, never said a negative word about anything.

“I got nothing but positive things for him, and I feel sure he’s going to get a good opportunity to at least compete for a starting job this year.’’

The Saints, Steelers, Seahawks (now without Russell Wilson), Buccaneers (Blaine Gabbert is the starter sans Tom Brady) or the Panthers (still with Sam Darnold) could make a run at Trubisky and offer him a much clearer path to a starting job. The Commanders on Wednesday traded with the Colts for Carson Wentz — does that mean the Colts would consider Trubisky? Other quarterback options other than Trubisky in free agency or via a trade are Jimmy Garoppolo, Teddy Bridgewater, Marcus Mariota and Jameis Winston.

On the day Daboll was introduced as the head coach, co-owner John Mara said, “Daniel will get a chance next year and we’ll hopefully be able to get a fair evaluation of him, and if it doesn’t work out, we’ll go to Plan B. But we have a lot of confidence that it will work out.’’

Mara also admitted the Giants had “done everything possible to screw this kid up since he’s been here.’’

Schoen last week said, “Daniel Jones is our starting quarterback right now.’’

If the Giants somehow find the salary cap space to sign Trubisky, “right now’’ might mean “not for much longer’’ for Jones.