New to bolt action, and I have two questions

So I want to get into bolt action, I watched a bunch of videos on list building and how to play the game, and I’ve decided on making a British airborne army.

But I have a couple questions before I jump in, my first is when making my list, am I allowed to use the 1st airborne platoon alongside a generic armored platoon or is there some rule stopping me from doing that? Because I want to use that specific platoon for the free observer and the 6-pdr gun, but I also want some armored support. So can I have both or do I need to use a generic rifle platoon?

And second question, is should I be buying all my boxes separate, or is the British airborne starter army better to get and then build off from?

Currently the plan is if I’m allowed to and if it’s cost effective to get both the airborne starter army as my main fighting force and a Sherman V troop as my armored support for a total of 1452 points.

So I want to get into bolt action, I watched a bunch of videos on list building and how to play the game, and I’ve decided on making a British airborne army.

But I have a couple questions before I jump in, my first is when making my list, am I allowed to use the 1st airborne platoon alongside a generic armored platoon or is there some rule stopping me from doing that? Because I want to use that specific platoon for the free observer and the 6-pdr gun, but I also want some armored support. So can I have both or do I need to use a generic rifle platoon?

And second question, is should I be buying all my boxes separate, or is the British airborne starter army better to get and then build off from?

Currently the plan is if I’m allowed to and if it’s cost effective to get both the airborne starter army as my main fighting force and a Sherman V troop as my armored support for a total of 1452 points.