How to make my team better in pokemon diamond?

You probably wanna take Feint off Monferno since you need real predictions for it. Alakazam isn't too great cuz it doesn't learn any good moves till lots higher levels. Heracross is a really good pokemon so you might wanna rethink it being an HM slave. And Murkrow is really good when it evolves into Honchkrow so you should keep that. And for the last Pokemon you might want too add an Electric type like Luxray it is very strong. Hope I helped.