15400 or 15450 for me?

[Timelessness]

Hello everyone, I am currently in the midst of getting a new RO in blue but I am not sure whether a 41mm or 37mm would suit me better.

I always thought I had fairly huge wrists, but this morning I measured them and realised I only had 6.3inch wrists

I previously owned a 15400 in grey and my friends all felt that the 41mm suited me very well, despite most discussions on the forums agreeing that the massive 15400 is more suited for people with 7in+ wrists. Maybe my wrists are flat, or this could be attributed to my body build? (I do a lot of weight lifting and have a fairly built upper body/biceps sans my wrist which I never train at all )

I recently sold my grey 15400 and I am about to get a new one in blue, but instead of getting a new 15400 I am actually considering the 15450 due to its cheaper price and potentially better fit for my wrist. I actually found one very cheaply priced (about 1k+ below market price) but it comes without the warranty card (although it does have the box and manual booklets).

As such, I would like to ask a few questions to the AP community:

1. Would a 15400 or 15450 be better suited for me?

2. Would it be recommended to purchase an AP without the warranty card? If someone had the papers of my watch and reported it as stolen would it be unfavourable to me?

3. Will AP still honor the warranty if I didn't have the warranty card? According to the seller it is a mid 2019 piece.

Thank you. As attached are some images of the 15400 on my wrist before I sold it for reference.