The "three month rule" specifically refers to the novel pickup request subforum. Novel Updates has a separate policy for listing with regards to casual, malicious poaching, and it makes much more generous allowances for competition. .... If you're looking for yet another novel to translate, though, I have a suggestion: Don't.
Because it's a bad idea. You're working on too many different things, not giving any of them the attention they deserve or require, and spreading yourself any thinner would be a mistake.