Ok first off my army consists of
Primary detachment
One Knight errent
Two Knight Paladins
AM detachment formation apoc (page 85)
Three squads of Three armoured sentinels
One Scout Sentinel
Three Enginseers with 2 servotors each
Now the issue i am having is this army classed as unbound or bound because from what i am told a formation counts as being bound but because i addid enginseers would they make this unbound at the moment for me its yes but also no.
The reason it is a bound army for enginseers is because they take up no slot and you may add them for each astra militarum detachment to a max of 3 would this still be bound?