The final years on Stafford's contract look similar to Teddy's, with the difference being $33M for 2021 rather than $24M. For 2022, both QBs are set to make $26M in their final playing seasons under contract with $5M in dead cap for Teddy and $6M in dead cap for Stafford. Stafford does have a $3M dead cap number in 2023.
Lions have a better salary cap situation than the Texans as well. ($3M under while HOU is $22M over).
Gives the Panthers an upgrade at the position but also makes it harder to sign other talent. I'd rather see Moton's deal inked before making a move on a QB.