Lashlee's system incorporates more running & is a far more effective rushing attack than the Briles system.
Lash is a Gus Malzahn disciple, he played for him in HS & coached under him at Arkansas, Ark St & Auburn.
His offense is a combination of the Arkansas rushing attack combined with the Sonny Dykes SMU Air Raid.
Briles system is just a variation of what his dad ran at Houston & Baylor, really it goes back to when Art was coachin HS down in TX back in the 90's & started going Spread while most of the other teams at that time were still running the Wishbone. He adapted it over the years & his time under Leach at TTech certainly impacted his style overall but at it's core it's still relatively the same system.
The difference is more of a reliance on the run game, Lash's system has a much more balanced Pass/Run ratio & is not the typical Pass only Air Raid that people usually confuse it for whenever they see those words. It's a high tempo based offense that's predicated on quick attacks & creating mismatches in the Defense by spreading the field horizontally with wide formations/alignments & forcing the Defense to pick their poison by committing to which attack they wanna stop. If they play double high then you hit'em up the middle of the field in the run & pass game, if they give you one on ones outside then you use you speed to beat them at the seams & win those one on one matchups.
Lashlee has coached versatile style offenses that have more Read option QB runs when he was at Auburn with Nick Marshall, so he can add that element to the offense with King, while still establishing the fundamental concepts of the SMU passing scheme in our offense as well.
As play callers, Lashlee is a lot more sophiscated & skilled than Kendal Briles, one of the main reasons why I had Lash in my top two OC's list is because from watching SMU last year you could tell he truly understands the chess match of football & understands the rhythm of a game, knowing when to call a shot, knowing when to be aggressive & go for the kill, knowing how/when to mix it up & keeping Defenes off balance. One of the major issues we've had is our play callers over these last few years always call plays with no rhyme or reason as to why, they just stick strictly to the play sheet & never adjust. Lashlee is the exact opposite, he calls what works & what's needed based on what looks he's getting from the Defense & what's happening in the game.
Briles is a bit of stat padder as an OC, high attempts to produce high yardage. Lashlee is calling the game to put the offense at the most advantageous situation to move the ball down the field & score.
I would say Lashlee's offense will be closer to what Oklahoma & UCF runs, Briles is closer to what TTech/Wash St & USC run.