LAPS Rejected. What now?

A proposal for LAPS was rejected by my manager. I just started my cybersecurity career. Only have offensive certs and helpdesk exp.
We have 1000+ machines with same local admin password.
Are there any other methods i can use to eliminate or reduce pass the hash attacks?
Please, any advice is a life saver

Just to be transparent. Nobody on my team understands things like DC sync, pass the hash or security in general. They do things like set passwords …

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