segwayguardsmenftw wrote:The real question is when does a units rules come into effect?
Ie: I think the argument should be made that you must take a unit before you can benefit from their rules; thus the bikes cannot be taken initially to meet the 4+ Troops component of the detachment.
HOWEVER
You could take 4 troops, a Captain on a bike and take 6 bike squads as fast attack choices - and those bikes would THEN become Troops choices and thus benefit from the Flock to the Front Line rule
But the question must be asked when a units special rules come into effect (ie during list building, deployment, etc.)
If what you propose were correct then Space Marine bike armies wouldn't work, and it is universally accepted that they do.