well, if you firstly send 3 - 5 troops into fungs, you have after 10 turns ~5 mindworms - enough to soften enemy at the beggining. then, after researching empathy choosing green enonomy and getting 2 - 3 foils, you go to sea fungus or new sargasso. after some turns you can easily catch 3-5 isles, with 2-5 worms each. after about 50 turns from planetfall it is really much, and enemy in 99% of possibility won't be able to defend himself.
cathing lifeforms on land with +1 planet is something completely different from cathing isles full of mindworms in sargasso when having green economy...