Greater Rift Help

I did a few Greater Rifts but it feels Like pure Luck. I either die floor 8 boss or floor 9 Trash Mobs. Could you Guys give me some advice.

I Always try to get a Team With cc, some Tanks, Support and 1-2 carrys. But as of now mage IS the only Altar that rly works for me.

Maybe wrong itemisation or under lvled cause of to many Heros or wrong Altar Combination? Idk