you should change it to dialga because its a dragon steel with no dragon weaknesses. pluse its got a good spec. attk.
a garchomp could kill dialga. ground is effective on steel u know.
all lv 100 rate my team from a scale of 1-10
lucario
tyranitar(shiny)(not trading)
salamance
garchomp
arcanine
dragonite
lucario- a good choise but quite overused 7
tyranitar- a quite strong pokemon but his speed might affect your battling 5
salamence- a very good choice 10
garchomp- his amasing speed may help you in tight spaces 9
arcanine- a choice that i would have made and he is quite good 8
dragonite i wouldnt have chosen him considering you had salamence, I suggest replacing him with a water type perhaps? 6
overall score 7.5