imo CCS- get rid of plasmas meltas are better, since you want rapid fire range for effective plasma usage , which means you will be in melta range anyway for 2d6 Pen and better monstrous creature killing or even a sniper rifle or 2 if they are meant to sick back give out orders, even a bare bones with vox is better, also with a chimera do you really need the medi pack ? (points)

leman russ squad is cool im not the most experienced with that, however pask in a vanquisher for not that many more points with 2 executioners + sponsons optional is the way to go from what ive seen, used, effectiveness, consistency the rerolls and a punisher with rending can take out av14 in a single turn let alone anything else

elites : scions are cool i like em depending on what your using them for here it seems like DS into tank/ high value target range and take it out, i like that i respect that, there isnt much to change im super fond of ratlings however (they have shit models though) they can snipe and run also BS 4 super annoying to get rid of and super strong at also taking out high value targets, WITHOUT suiciding themselves

heavy - wyvers are so cool i love them, hydras less sold on they are meant for one purpose and one purpose only, and lack everything else, i would only just take more standard leman russ' yes more expensive, but the value of an S8 AP 3 blast is undeniable dont take sponsons , no more lumbering behemoth kinda killed that, IF YOU MUST TAKE THE HYDRA, i suggest camo cloaks + aegis defence line, hunter killer missle is no longer as stronga s it used to be, get rid of them simple as that, better points else where,

on a side note, competitive list with no aegus ? also less plasma guns they just arnt that great with imp guard ive tried on so many occasions and just get better results with meltas or conscripts to move up the line with a priest making them fearless, overall its a pretty set list on taking out high value targets quickly and flying units which is great, i think you would have a serious, serious problem vs horde armies, you can argue the wyverns but against a competitive list they will simply DS/ target the wyverns first since they have kinda meh range then a green tide formation for example would simply over run you, i like the idea it does need changes however, man 1 hydra or replace both with an aegis defence line and the turret, keep the chims back and use them for objectives later, thats mostly what i have to say, i can give a ton more tips if you wish, 10years of IG/renegades/chaos in all its glory experience :)