IMO, closing your oldest card may not be the best idea. That will dramatically change your AAoA which will in turn reduce your scores, if it's significantly older as you state. It's according to the age really.....if it's 5-10 yrs older than your other cards it will hurt....if it's only a year/2 at most, then maybe you can weather it. But you also stated it would cut your total CL in half......if you do all this, I would suggest getting that US Bank Cash+ first, because your scores will likely tank afterward.
But you ultimately have to do what you think is best for your needs.
My oldest card is a lower APR SmartOption card (in my sig) and although it's my oldest, it's also my lowest CL ($2,500). Wish I could dump it but I know it will kill my scores if I do. Requires a HP to get a CLI for it, so I've held off.....there are other cards I would rather use my HP's for.
On Deck: No Plans Currently
Unless I'm misreading, OP is just talking about consolidating spend on 4 cards, not closing any.
@Anonymous wrote:OP, could you please clarify if whether you just plan on putting some cards in the SD or closing? If the latter, I agree with the 1st post and not closing your oldest account as it would significantly decrease your AAoA, thus taking a hit to your scores for some time.
@VanderSnoot wrote:Any dos and don'ts of simplifying your card lineup? A quick review of my lineup shows I can get most of my current rewards with about 4 or 5 cards from 4 issuers (the difference is getting a second US Bank Cash+ card). It means ditching rotating category cards, including my oldest card (by a significant margin) and it moves me decidedly towards Amex, a smaller network than Visa or MS (but my default 2% card would be a Visa). My total CL would roughly halve, and utilization would not be affected significantly. I would SD, rather than close, other cards and let them close on their own. All thoughts are appreciated.
@seattletravels wrote:
@Anonymous wrote:OP, could you please clarify if whether you just plan on putting some cards in the SD or closing? If the latter, I agree with the 1st post and not closing your oldest account as it would significantly decrease your AAoA, thus taking a hit to your scores for some time.
@VanderSnoot wrote:Any dos and don'ts of simplifying your card lineup? A quick review of my lineup shows I can get most of my current rewards with about 4 or 5 cards from 4 issuers (the difference is getting a second US Bank Cash+ card). It means ditching rotating category cards, including my oldest card (by a significant margin) and it moves me decidedly towards Amex, a smaller network than Visa or MS (but my default 2% card would be a Visa). My total CL would roughly halve, and utilization would not be affected significantly. I would SD, rather than close, other cards and let them close on their own. All thoughts are appreciated.
Wow, I was still half asleep when I read OP's post. Ridiculous 
@Anonymous wrote:
@seattletravels wrote:
@Anonymous wrote:OP, could you please clarify if whether you just plan on putting some cards in the SD or closing? If the latter, I agree with the 1st post and not closing your oldest account as it would significantly decrease your AAoA, thus taking a hit to your scores for some time.
@VanderSnoot wrote:Any dos and don'ts of simplifying your card lineup? A quick review of my lineup shows I can get most of my current rewards with about 4 or 5 cards from 4 issuers (the difference is getting a second US Bank Cash+ card). It means ditching rotating category cards, including my oldest card (by a significant margin) and it moves me decidedly towards Amex, a smaller network than Visa or MS (but my default 2% card would be a Visa). My total CL would roughly halve, and utilization would not be affected significantly. I would SD, rather than close, other cards and let them close on their own. All thoughts are appreciated.
Wow, I was still half asleep when I read OP's post. Ridiculous
Could you clarify? 
@Anonymous wrote:
@seattletravels wrote:
@Anonymous wrote:OP, could you please clarify if whether you just plan on putting some cards in the SD or closing? If the latter, I agree with the 1st post and not closing your oldest account as it would significantly decrease your AAoA, thus taking a hit to your scores for some time.
@VanderSnoot wrote:Any dos and don'ts of simplifying your card lineup? A quick review of my lineup shows I can get most of my current rewards with about 4 or 5 cards from 4 issuers (the difference is getting a second US Bank Cash+ card). It means ditching rotating category cards, including my oldest card (by a significant margin) and it moves me decidedly towards Amex, a smaller network than Visa or MS (but my default 2% card would be a Visa). My total CL would roughly halve, and utilization would not be affected significantly. I would SD, rather than close, other cards and let them close on their own. All thoughts are appreciated.
Wow, I was still half asleep when I read OP's post. Ridiculous
Here you go. This should help ☕️☕️
😁