Question about units composing a battalion

[Arkalid]

Okay, so I just started the game, so bear with me even if this is a stupid question.

So, I take a Battalion Warscroll. For example a Temple Nest Battalion, which includes a Bloodwrack Medusa, 2 units of Blood Sisters and 2 units of Blood Stalkers. My question is this: do I have to take those exact 5 units, or can I take  something like the Medusa and just 2 units of Blood Sisters, but no Blood Stalkers. So are the Battalions specific formations, or more like 40K force organization charts where you may take units up to the stated limit?

[Overread]

For a Battalion you must take the exact units as outlined on the battalion warscroll page. 

Unless a model count is stated those units can have any number from their minimum to maximum number of units within them. Furthermore if the keyword in the description is written in bold then you need only that key word in the unit to take. So for example in a Temple Nest Battalion the Bloodwrack Medusa is in bold and thus you can take a Bloodwrack Medusa or a Blodwrack Shrine. 

In addition some of the Temples can affect them, for example if your army is from the Khailebron Temple you "can" have up to 2 additional Melusai units (where Melusai is bolded and thus it can be any unit with that key word; so blood sisters or blood stalkers). The Temple effect is a "can" and thus its optional and not mandatory. 

 

However to reinforce; what's on the Battalions page is mandatory and not optional. 

[rokapoke]

The battalions have set requirements. Some will indicate ranges instead of specific numbers, but you must satisfy all requirements; you cannot just pick and choose.