I don't think Lashlee is anything special.
Sonny Dykes's career as a HC:
--Year ---------Schoool------Total Points--Total Yards ---Yards/Play---Pass Yards---Rush Yards------Rush Y/A-----First Downs-----Turnovers
2010 | LTech | 59th | 49th | 72nd | 62nd | 40th | 51st | 41st | 105th (Bad) |
2011 | LTech | 43rd | 52nd | 81st | 45th | 70th | 88th | 62nd | 37th |
2012 | LTech | 1st | 1st | 9th | 3rd | 17th | 17th | 1st | 14th (Good) |
2013 | Cal | 97th | 34th | 96th | 10th | 107th | 106th | 23rd | 112th |
2014 | Cal | 10th | 14th | 33rd | 6th | 13th | 34th | 7th | 69th |
2015 | Cal | 17th | 8th | 6th | 3rd | 92nd | 62nd | 10th | 94th |
2016 | Cal | 22nd | 10th | 55th | 4th | 88th | 65th | 3rd | 44th |
2017 | SMU | 13th | 15th | 19th | 19th | 42nd | 31st | 16th | 73rd |
2018 | SMU | 54th | 81st | 94th | 27th | 119th | 121st | 89th | 28th |
2019 | SMU | 7th | 9th | 45th | 13th | 44th | 65th | 10th | 55th |
Green= Performance basically as good/better than under Laslee in 2019. Red= Way worse. Yellow and Orange are in-between, obviously.
Lashlee was the SMU OC in 2018 and 2019 (Bolded in the Chart), but I actually only did the colors based on this season, because 2018 they were trash - Even though in 2017 SMU was as good or better offensively (without Lashlee) than they were this year.
So In 2017, SMU is really good on offense - pretty much as good or better than this year across the board. Then 2018 Lashlee comes in and they regress. Then in his 2nd year he gets them back to where they were before he was there. PLUS, all they did this year, pretty much matches what Dykes was able to consistently do in his career. Like legit even the Bad years for Dykes (2010, 2011, 2013) were no worse than Lashlees first year as OC. And when Dykes had Goff as a Sophomore and Junior in 2014 and 2015 respectively, then 2016 with Davis Webb, Cal had one of the best offenses....
IMO getting Lashlee is nothing more than just getting the Sonny Dykes/Hal Mumme/Mike Leach system. I doubt Lashlee is anything special as a play caller/qb coach. Dykes/Leachs QBs always do well due to the scheme. He had Jared Goff and Davis Webb . Only real difference between Leach and Dykes is he likes to run the ball more than Leach, which is why Lashlee fits his overall scheme, coming from Auburn under Malzahn, where it's about No huddle and trying to get a Run/Pass balance. Sure they aren't running a pure "air raid" but Dykes wasn't at Cal either... The entire scheme is no huddle, trying to run as many plays as possible, and few actually different plays, just executed really well with multiple options for the qb to choose in each play/at los.