Is were anything that can be done about the Graphic cards they are all falling down at the ends the different is about 3 mm from were they are screwed in ?
As Tom says considering the cards don't have backplates and aren't joined together in any way that's totally normal for them to flex that much when fitted with heavy blocks.
One thing which may help would be solid tubing between the cards however there will still be a little flex in the rubber seals. More or less the best thing you can do without any weird mods would be to fit an FC-Terminal bridge which secures each GPU block together effectively holding them all parallel to each other, teamed with then having effectively six screws spread out holding the whole unit of 3 cards to the case that's about as solid as you can get them.
There are a number of options with different internal arrangements, spacings, finishes and materials. It's a rather different aesthetic to linking each card with fittings but it can look great. Personally I think with 3 cards they are so close together that fittings look very cramped. They are pretty cheap considering they save the need for 4 or 8 fittings.