I don't think anybody will be able to tell you much without some pics. Are you able to share some?

Moss. Will potting plants together be temporary, or are you planning on keeping all as, 'dishgardens,' indefinately? Toni

I was just outside watering my porch plants and thought of your question because I have a few "combo pots." So I realized I have some general advice that may help. Plants with similar needs (light/water) should be grouped together. If you juggle some tall plants, and some short, you can fit more in each pot. The philodendron and english ivy can be transported as cuttings in water if you get really desperate for space. When I have to move plants in a moving truck, I try to pack the back of the truck with the plants in mind, so they have a place to sit where they won't be able to tip over. A laundry basket or box can help several pots hold each other up. Put each pot in a plastic bag, leave open, but pull the plastic as high as possible. If anything does tip over, the dirt will stay in the bag, and the plastic sheath may help prevent breakage of stems.

I just thought of another way to transport your plants..'instead of potting together.'

I used to work at a plant store. Every plant that went out, in spite of size, were placed in Pot Sleeves.
The sleeves come in different sizes, from 4" up.

A plant is carefully placed in the top of the sleeve, and if the correct size sleeve is used, lowered and caught at the bottom of the container. The top can be stapled closed.
If a sleeve is too large for a pot, the bottom is stapled so it doesn't slip through.

I've seen these sleeves for sale, but that was some time ago. You can check Ebay or Google Pot Sleeves. Toni

Thanks for the advice. I would probably be leaving them together for several months. I guess I can just consolidate the ficuses with the dracaenas and put the philodendrons together, I'll probably trim them down significantly and transport the bulk as cuttings in water like purpleinopp suggested.

Does anyone know if a money tree plant and a mother-in-law's tongue can cohabitate?

a money tree plant and a mother-in-law's tongue would probably not go well together, The money tree plant is a swamp native, meaning damp and the sans is from dryer areas in africa, they have very different needs.

The vineing type plants will travel well bare rooted wrapped in damp newspaper or moss and then rather than a jar or vessel of some type, just set them in loose damp sphagnum (not peat) moss and let them grow like that, you don't need to cut them unless you feel they're too big or want to increase them with new cuttings.

In fact, if you aren't going to be traveling more than a few days with them you can probably sent most of them bare rooted and then repot them when you get where-ever you are going.

Maybe not the ficus but I have a bias with them, They drop dead if I look at them.