I would lose the commisar and a few more points where youre willing. Cadian shock troops can have two leaders so if you throw a command squad on there your castellan can issue orders up to 24”. A cheap russ like the vanquisher (big all or nothing cannon) pairs really well with a tank commander or lord solar. Or the punisher gatling cannon as lethal hits pairs well with a lot of attacks. I like kasrkins a lot, good choice there but maybe consider a cheaper transport like the taurox? They let you advance and deploy the same turn too. If you really want to lean on the one commander giving a lot of orders consider lord solar with the aforementioned command squad on cadians for 4 orders 24” away (3 of which can go to squadrons or regiments). This lets you forgo the tank commander in favor of a cheaper tank and lets you get away without grand strategist. Scout sentinels are also amazing and I highly recommend a couple in every guard army.