Spatterdock, eh?
Good plant for your lake. It's not invasive where you live because it only likes peripheral shallow water. Your water goes deep fast, places where spatterdock won't go. Good choice.
Adding a different lily type plant changes the equation, and the dynamics. You see, different plants have different requirements. For example, American lotus can grow anywhere the sun penetrates, and grow quickly. I worked a lake two years ago that was 75% covered with lotus. Too much shallow, fast growing plant life. Fragrant white water lilies, while less invasive, still grow in deeper waters than spatterdock. So, before transplanting, identify the plant and learn its growth characteristics.
Fish benefit several ways. Baby fish hide. Baby fish live longer, grow larger. Bass eat baby fish. Spatterdock good.
Pick another lily? Call a water garden shop, get a book on life histories of different lilies, and compare those plants to available habitat. Then, you can make the best decision. Also, talk to water garden types, ask them growth characteristics of different lilies. Some are tropical, some are semi-tropical. Some live three months of the year, some longer. Some bloom at night, some don't bloom at all.
Beaver, ducks, nutria and turtles pull up plants. Best successes I have seen are people who plant in containers, or beds, then cover the containers or beds with wire nets or fences called "exclusion" fences. Keeps creatures out, while plants establish.
Spatterdock hasn't migrated because it has no means. It was transplanted, and has probably grown to its maximum for that area.

Teach a man to grow fish...
He can teach to catch fish...