Paul,
If your pump is cutting out, you have a problem somewhere for sure as that shouldn't happen. If the pump you have is running properly you have tons of vacuum.
Everyone thinks you need 12 pumps all lined up and they all need to be 40 hp each. But this is not the case at all, 1 or 2 pumps is tons of vacuum.
I am not familiar with your cnc, but you said you have a 5x10 table, how often do you cut 5x10 sheets? maybe you cut bigger sheets all the time , but a lot of people cut only 4x8 sheets on a 5x10 machine, you have 50 sq ft of table but you only need 32 sq ft of vacuum. Shut down the extra 18 ft that you don't need. Like I said I don't know your machine, but many tables have zones you can turn on and off, some machines have plugs you can use to isolate areas, or you can be creative and tape poly on your spoil board or use a piece of laminate or plastic sign material to cover the area where you don't need vacuum.
Another big problem for a lot of people is the condition of the spoil board, number one is it machined regularly, if it has a bunch of tracks in it, and if your operator is cutting to deep then the tracks are just wasting vacuum. Is your spoil board clean, what do you do to prep it in between sheets? There are not many sweeps or dust collection systems that clean the board sufficiently to just through a new sheet down and cut again. I recommend a quick vacuum, I use a metal wand with a brush that has wheels in it. I have a port that ties into the dust collector, it is very quick.
If you have to cut a bunch of tiny parts then like others said, onion skin , or isolate one small corner of your table and cut those parts separately.