Witch Infernalist Flaming Minion Build Feedback

So I am making a demon army minion build with the Hellhound and the regular skeletons with the support gem that burns them for 20% of their max health to do the same amount of fire damage in 1.5 meters.

My problem, after some testing and stat sheet studying and several respecs, the build needs help. From GGG specifically. The fire damage only scales to minion max health and % minion damage and % fire damage does not help the build. I haven't confirmed if % ignite magnitude would help, but I suspect it won't. Another problem is that there aren't enough support gems for these little guys. I have every single one that works with them and it isn't much. If I ever get my hands on a greater jewelers orb I won't even have another support gem I could use for my minions.

My witch is level 52 right now and I am also using her as a sorceress for more DPS and so I don't get bored. At level 12 (14 with +2 minion level) my Hellhound has 5000+ health and does 1216 of fire damage in 1.5 meters. At the same time, my skeletons have 3552 health and do something under a 1000 in 1.5 meters. I have MOST of the % minion max health, so if the skeletons health is a small curve at the higher levels, it will be a problem late game.

I never got on the arsonists band wagon, but if GGG doesn't want everyone spamming them, they need to balance the other minions. This is sincere feedback, I'm not bashing them. Please save my build before I have to swap! We need more support gems for minions. What am I supposed to do here?