Rhodian marines are kind of average at best.
Their armor is 25 but they look more armoured than 30 stat marines, maybe upgrade them a bit. Their 28/2 damage model should probably be replaced with 26/4 damage model or at least a 27/3 model.
Other stats are fine.
Also , their land garrison marines are 80 man units (highest unit sizes) for some reason, no other faction has that low number.
Any chance for a updated marines?