Hey Konstantinos,
You can check everyday and probably there are new strategies being generated for each timeframe almost everyday depending on if the current strategies are profitable or not. It could be that a strategy in M1 could be profitable for 1 or 2 weeks for example.
About choosing between W1 or D1 I think that W1 gets more data which means that it can perform better than D1.
Hope this helps!
Kind Regards,
Nikos