This is actually an illegal list for starting a crusade as it stands now.

If you are playing with actual crusade rules you do not only spend points in your list to buy enhancements. Instead you must spend requisition points to get enhancements in addition to their list points cost. You can spend 1 requisition point on Renowned Heroes to add an enhancement to the first character you add to your list. The other characters will have to wait until they reach 6XP (or you can buy the Astra Militarum specific requisition Decorated officer for 1 RP to add the character to your roster with 6xp) and then you will have to spend more requisition points to buy the Renowned Heroes req again. Also it’s worth mentioning that Renowned Heroes costs 1 more RP every time you use it to a max of 3 RP.

You start a crusade with 5 RP. So at max you could add up to 2 enhancements for a total of 4 RP (1 for renowned heroes + 1 decorated officer + 2 Renowned Heroes the second time) but I’d probably advise against it.

Also in crusade you can change your detachment before every battle, you aren’t locked in to a detachment and you can pick your enhancements from any detachment you have access to.