two smaller braces are setter then one single in the middle its spreads the load along a larger area, but then again 3 is beter then two..., bit the more you put the harder it is to add lights, well for some people, its going to have a glass lig anyway right?, also turtls dont need much light anyway, not like they bask right?
EDIT: by"two smaller braces" i mean each about 2-3" wide...