>>48407959>TorterraNecessary for most poison types
>TropiusNecessary for most bug types
>RotomNecessary for most flying types
>RoseradeFast, poison immunity and nice alternative to check bugs. Also is more effective than wormadam and tropius at checking oposing grass types.
>TangrowthNo significant type advantadges, but a bulky alternative that will take most neutral attacks better than the rest, wide coverage too.
>WormadamJust filler, you should just box it whenever you manage to get anything better.
>overallYour team is vulnerable againt ice and fire.
For ice, the best you can get is abomasnow, because it will put you on an even ground with most ice types, where you'll both hit for neutral stabs. Change wormadam for abomasnow.
For fire, torterra should in theory not be reliable against most fire types, but because this is Sinnoh, it will be enough. If the remakes add more fire type pokemon, you should consider cradily, rock has amazing synergy with grass, and it will deal with both fire types and flying types, as well as checking bug and ice. If you want, change wormadam or rotom for a cradily.