Unlike caves, in which you can set up to "dive the cave" by wearing appropriate sidemount or back gas configurations, drop deco bottles at your exit, and most often have other divers' experiences from which to draw as to where and when to stage or where to drop stages, wrecks present a challenging exercise requiring the diver to often improvise, adapt and overcome when facing penetration.
As a rule, carrying all gas is the best way to go. But, if you require additional stage or bottom gas, tight shipwreck confines will often be easier to navigate without additional bottles.
When I need to drop bottles, I place them just inside the wreck. I create what I call a "gun rack" by running the guideline from open water to the secondary tie-off just inside the wreck, and I run the line from low to a midpoint on say, a bulkhead, at an angle that allows the bottles to be stacked valves down and secured by both nose and tail clips. The bottles sit atop one another nice, tight, and slick off to one side and out of the way of others who might end up swimming into the wreck by the same entry way. It is really great when you have a team of two or three because everyone's bottles are out of the way and clipped off on both clips out of the way and out of the current.
I'll drop the deco bottles or an added stage like this, but I will take a stage bottle with me during the swim. I tend to dive my bottom stage and then switch to deco leaving my back gas untouched. If I cannot return to the deco bottle or if it is lost or malfunctions, the untouched back gas should be enough for my deco obligation.
When swimming with the stage, I can move it in front of me or move it to the rear crotch D-ring in tight spaces.