A simple and cost-effective CloudM alternative is Movebot. Movebot is completely cloud hosted and managed there is no need to run your own infrastructure or spin up your own servers. Movebot is also 70% more cost-effective than CloudM as you only pay per GB and not per user/seat - as well there are no subscriptions. Additionally, Movebot supports you with your migrations and offers real engineers for support and is a widely used data migration tool by service providers globally.
Another option that you have is the ability to run a preflight discovery scan across your source platform which performs a discovery scan of your source data platform and will show you any errors that may be encountered, a breakdown of the data structure and information on the content.
Movebot keeps migrations simple, whether it is, hundreds of users or thousands of users, on-premise to the cloud, or cloud to cloud. It's always simple, fast and cost-effective.