T1 ET visa duration ( apply for 3 years or 5 ?)

Hello !
I am new to this group - I've followed the posts and am grateful to contributors of this group - Have received a lot of insight from the posts. Thank you!

May I post a request for clarification. I couldn't really get an answer to this question in existing posts

Am in the process of applying for a visa. Since a T1 (exceptional talent) holder can apply for ILR in 3 years- what are the considerations for his dependents. As I understand - I need to choose the better of the following 2 options:

1) should they apply for 3 years initially and apply for 2-year extension at the same time (that the visa holder applies for ILR). Is there a risk to process both applications together?

2) Primary applicant and dependents apply for 5 years initially. Primary applicant starts processing his ILR at the end of 3 years (while his dependents wait till 5 years to process ILR). Is this arrangement possible? The flip side is 2 years of extra health surcharge is lost for primary applicant and there is a higher total cost initially. Also - have I missed anything here?

Please comment. Thanks in advance.

You are right. Please go with option 1 which will save some cost for you.