Any Benefits of Converting 2 Existing Physical Networks into VLANs ?

Hi guys, I recently inherited an environment that was setup with 2 physical networks that operate side by side, both on unmanaged switches. The primary network is for all domain joined systems operating on the 192.168.1.1 network and all the other devices be on the 192.168.2.1 network. This includes things like Wi-Fi APs, wired kiosks, and laptops. I plan on purchasing managed switches to create VLANS for the Wi-Fi to be able to use some of those laptops to login to our domain. I would create another 192.168.3.1 VLAN network and put the guest Wi-Fi on that. Would there be any benefit to adding the existing 2.1 wired network devices into say the 3.1 or maybe even create another 4.1 VLAN for those devices?

I hope I'm painting a clear picture. I've never done a migration like this before but I feel like with my understanding of VLANs it shouldn't be too bad. The only real benefit I see to combine the wired 2.1 devices would be having more information gathered by the managed switches