Thank you for the opportunity to help you with your question!
Yes one group of invasive species can be worse than another because, depending on the environment it invades, it can wreak havoc and can disrupt the delicate ecosystem. Depending on where a specific group is placed it can create different amounts of disruption.
Please let me know if you need any clarification. I'm always happy to answer your questions.
By disruptions i mean the ecosystem loses equilibrium. For example Zebra Mussels are an invasive species, and they take in some toxins for the Great Lakes. This is transferred to the other fish who eat the Zebra Mussels, and then to bigger fish that eat the smaller fish who eat the Zebra Mussel. It can cause a decrease in population for many species.
An example of one group would the Purple Loosestrife. This plant invades marshes and swamps and replaces wetland plants. Purple Loosestrife is found all along the East Coast of the United States. However if you were to place it to the East coast, it would have minimal effect of the environment, since there are little marshes and swamps there.