I really do hope you have lots of fun with this list, but it isn't efficient or competitive for the most part -
- Sniper Rifles aren't that good as you'll need 3 of those Squads to all focus their fire on a single enemy MEQ unit to do any decent damage at all...simply not killy enough and are far poorer than all the other SW's other than GL's. Add Cover to the equation and it gets even worse.
Ratlings, while not great is the best place to get Snipers on the field...for Vets they're a waste - Plasma/Melta only.
Good SW combos for SWS units are a mix of Flamers, Meltas, and Demo Charges.
While the PCS is ok as-is, some Flamers does mean they can act as a counter assaulter/protector for your Infantry...works well I've found, even on foot.
Not that I'm a fan of GL's but they are a good match for Harker's HB.
Doctrines, while fluffy, are mainly points - sucks...more bodies on the ground, and/or more efficient SW's is far more productive and thrifty.
My 2c anyway...best of luck with your plans