dojo decorations don't allign

[The_Shapeshifter_Aku]

i'm trying to decorate my inspiration hall. i use orokin walls and catwalks. but i can't place decorations how i want even with restricted movement menu. i know i can overlap decorations. most of the time i can overlap the edges of these. but sometimes no mater how much i try with restricted movement or with free movement i can't put them on the floor near the others. restricted movement just stops advancing and free movement camera is odd and the decoration just goes all over the place with minimal mouse movement and never in the desired spot. is there any better way to place decoration? is there any script/tool that can let me place decorations at specific coordinates?
i attached an image that shows my problem (i can't place the orokin wall on the floor to make right angle with the other). what can i do to see my project to the end without wasting 30 min on each wall/catwalk ?