Why does ECS Task Definition accept roles arn OR name, but Batch Job Definition only accept roles ARN?

Hello,

This inconsistency between ECS and Batch is quite inconvenient for our multi-account CI/CD. There is no clear documentation from AWS about ARN vs Name in definition files. It is supported in one, but not the other.

This task-definition.json works for ECS:

{
    ...
    "taskRoleArn": "[TASK_ROLE_NAME]",
    "executionRoleArn": "[EXECUTION_ROLE_NAME]",
    ....
}

But trying to register a similar job-definition.json to Batch returns this error:

Error executing request, Exception : executionRoleArn batch-job-execution-role-dbt-runner is not an iam role arn, RequestId: c55d9c71-c330-4f8a-9043-b0956267b482

Thank you