Just seen a q from NH in a different thread, here is the response copied here as well.
Don't know how I missed the reply, I blame the new posts button!
The biggest problem was the WE. The formations couldn't do enough damage in a straight up firefight to beat them (though note the nid WE stats here were horrendus). Against the swarms it was a FF clipping assault field day, but anything left in range shredded a formation in return.
With next to no incoming fire the rhinos never died and this gave the army excellent mobility, often with marines staying in transports for devestating 50cm range firefights. When the nid attack developed the army was able to completely bypass the main thrust, with key formations remaining dangerous until late game (when the WE finally gobbled up a fair chunk of them).
The nid list negated a lot of the potential strengths though. The sallies couldn't mass to much to form a devastating firebase due to the WE threat, though of course I had mobility instead.
The firepower was if anything slightly less than a regular marine army, with 15cm weapons on the preds, extra marines and termies. Generally if I was in range to shoot I was in range to assault, though this is against an aggressive army. Against a different force though doubling and shooting might happen a bit more - though here you have to balance -1 to the missile launchers against the benefit for the multi melta to fire.
The more I use it the more I hate the multi melta! Getting in range means getting in CC range of the enemy. The lowered FF/MW combo works I think now the upgrade cost is lowered. Still its largely an extra bodies boost, with the MW attacks not really benefiting the formation much (who wants to see the numbers for 4+ vs MW5+ ?
). Maybe the cost should go back up (and knock on costs like th expensive thawk come down) and the FF be raised to Tac/Dev normal amounts?
Activations and cost was a big headache. On reflection I wouldn't have bothered with the extra preds for the assault marines and gone for Chaplains for two formations instead.
Oh and the teleport, recover, assault, tactic worked perfectly!
Ultimately I see the main enemy tactic being kill the rhinos, kill the supporting formations, avoid the infantry formations until you want to fight them. Conversely the main Sally tactic seems to be using the support formations and cover to tie up enough of the enemy to allow the big formations to get to attack range, with a definite bias therefore for terminators and warhounds and maybe a brace of speeders.
One thing the army does is take casualties! The loss of some of the marine flexibility for bigger formations seems to result in far higher casualties, even for me and I can be an atrocious marine commander!
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If using E-Bay use this link to support Tac Com!'Abolish red trousers?! Never! Red trousers are France!' – Eugene Etienne, War Minister, 1913
"Gentlemen, we may not make history tomorrow, but we shall certainly change the geography."
General Plumer, 191x
But else i like the design of the flags 
And your paintjob too off course 
