I agree with Fragger being a good choice if you want some similarity to Skyhammer’s guns. Fragger just has a grenade so there is not massive damage all around, but the direct hits are devastating. If you like the massive airstrike type damage, there is also Arty whom I believe is 30k and is a bit like a mini Skyhammer in that regard, but not as durable as Fragger and his 150hp and loadouts.
I think you would really enjoy Stoker to be quite honest, based on your “especially when enemies are camped together” statement and his molotov fire can definitely work to that angle, especially for defensive roles like throwing fire on a c4 to prevent someone from defusing, or blocking a path for the enemy rushing in. There is also the fact that by default, Stoker uses the Timik/AK 47, if you really like that gun as indicated.
There are a bunch of mercs on free rotation so try them out as well, see how each plays. I hated Redeye at first when he was on free for the first time, but I decided to try him again some days after and lo and behold got the hang of him and he was fun. He has been my main since, with 5000+Kills logged.
The choice is up to you in the end and what you like, but I strongly feel Stoker will appeal to you the most at this time based on the statements you have provided.