How do the lambda function and lambda layers quotas work?

I see that the docs state:

50 MB (zipped, when uploaded through the Lambda API or SDKs). Upload larger files with Amazon S3.

50 MB (when uploaded through the Lambda console)

250 MB The maximum size of the contents of a deployment package, including layers and custom runtimes. (unzipped)

Give this information, is my below understanding correct?

Let's say I have defined the below in a cloudformation/stack.yml to be deployed with SAM CLI

Lambda Function 1
Lambda Function 2

Lambda Layers 1 - x86
Lambda Layers 2 - arm64

I would understand that this means:

• Each individual function should be smaller than 50 mb as a zip

• Each individual layer should be smaller than 50mb as a zip

• Lamba Function 1 + Lambda Layers 1 (unzipped) should be smaller than 250mb

• Lambda Function 2 + Lambda Layers 2 (unzipped) should be smaller than 250mb

As I understand, if any of the above are false, I should fall back on S3, but what is the max size (zip and unzipped) if my layers are on S3?

Are all of the above correct?

I'm surfacing this concern because my current approach using SAM CLI allows me to deploy:

Lambda Function 1 + Lambda Layers 1 
AND 
Lambda Function 2 + Lambda Layers 1 # only one layer deployed

BUT DOES NOT WORK AS:

Lambda Function 1 + Lambda Layers 1 
AND 
Lambda Function 2 + Lambda Layers 2 # trying to deploy the same layer with different arch simultaneously

Error:

CREATE_FAILED                            AWS::Lambda::LayerVersion                LambdaLayer2<some_id>             Resource handler returned message:
                                                                                                                           "Unzipped size must be smaller than
                                                                                                                           262144000 bytes (Service: Lambda,
                                                                                                                           Status Code: 400, Request ID:
                                                                                                                           <some_id>)
                                                                                                                           (SDK Attempt Count: 1)" (RequestToken:
                                                                                                                           <some_token>,
                                                                                                                           HandlerErrorCode: InvalidRequest)