weak to poison due to pesticides. ya kno, like, agriculturally.
anyway, grass shouldn't be weak to steel, because that is kinda too general. also, fire should be weak to flying water rock, not ground water rock. the gusts would put it out, but an earthquake wouldn't affect a fire, the rocks in the earthquake would affect the fire. finally, water having only two weaknesses is ridiculous, because thts too small for a starter. it should be hurt by poison. like oil spills and stuff. it contaminates water itself, and KILLS the animals and fish living in the water. like, how did nintendo not realize that one. LOL. but yea, its unfair tht grass has 5 weaknesses. Altho, im more of a fire guy.
EDIT:
WHAT?!? yEA OK THAT MAKES SENSE. 1 OF 3 STARTERS ARE GOOD. aright, first off, grass is amazing, considering it beats water types! lets see if ur Swapmert or Blastoise will withstans a solarbeam from venasaur, or a frenzy whip from sceptile. next, fire types kick ***! what, charizard isnt awesome enough? blaziken doesnt cut it? then what does? ok lets get real. all the types are equal (except for bug. we all hate u bug types!

LOL) anyway, fire grass and water are equal. i think there should even be the move boil, cuz fire can vaporize water, so in reality, there equal. in quantity, and quality. but, since u said water is the strongest, let me play devil's advocate and say tht water is the worst. LOL