Desde hace

Desde hace
 

1. Pedro y yo nos conocemos desde hace muchos años.
2. Pedro y yo nos conocemos hace muchos años.

Am I right in saying that number 2 above is incorrect? I think in order for 2 to be correct, the verb form would need to be ‘conocimos’.

Many thanks in advance.

You are correct on both counts about sentence 2.
However, "Hace muchos años que Pedro y yo nos conocemos" is correct.

Thanks so much, Rusty. Really appreciate your help.

I agree that grammatically No. 2 might not be great, but daily speech allows it.

If you say "nos conocimos hace muchos años", you're changing the meaning, even if you have a better sentence. :D