Normally I would completely agree with you but the OP did specifically mention that wired memory usage was high. On OSX at least this refers to memory that is in use by the kernel/OS and can't be swapped out to disk. I don't know for certain but I would be somewhat surprised if this memory could be reclaimed in the same way as the memory used by normal apps. Maybe the OP is hitting a bug in iOS that is causing the kernel to grab wired memory and not give it back. Over time that could reduce the memory available to apps so much that the iPad starts running badly.
iOS doesn't manage memory the same as OS X. It doesn't use virtual memory and swap out to disk at all. In this case, as it's low on memory, it would work like this:
1. He opens infinity blade, which asks for a whole load of RAM.
2. The OS checks, and sees that it wants 10x more RAM than is available.
3. It checks which apps are currently open in the background, picks the one that hasn't been used for the longest, and tells it to quit.
4. That background app 'wakes up', saves its state (so if you were in the middle of a game it resumes where you left off), and quits.
5. The OS passes the freed up RAM to infinity blade.
6. If there's still not enough free, go back to 3 and repeat.
So basically it keeps killing old apps until there's enough memory left. If you watched it, you'd probably see the wired memory stay at 90%+ the whole time, yet a large game can still load into memory.
The only real downside is that the game might run poorly to begin with, because it's still loading bits into memory and other apps are silently shutting down in the background. Give it a little time though and it's back to normal.