Is it acceptable to use deadlocks as a strategy?
Snapshot and Read Committed Snapshot isolation levels do not prevent deadlocks from happening. They make the engine using row versioning, so readers do not block writers and writers do not block readers as SQLServer does by default. That improves concurrency , but requires changes to the applications that rely on  "readers block writers and writers block readers" . I guess you misunderstood your manager , and your system relies on that SQLServer default blocking behavior, not on deadlocks which in most cases can be avoided by application design. 

If I happen to work with SQLServer on a new system, I'll surely switch it to use row versioning instead of locking. 

However, for an existing system, it is usually safer and cheaper not to fix what is not broken (especially when it's not broken).