What's your question? Ask

Your images show two different plants; Rubber Tree and a Bird of Paradise.
These links will help refresh you on the care.
https://www.gardeningknowhow.com/houseplants/rubber-tree/how-to-care-for-a-rubber-tree-plant.htm
https://www.gardeningknowhow.com/ornamental/flowers/bop/bird-of-paradise-as-a-houseplant.htm

Yes the rapid growth can be normal with good soil fertility and watering. But growth may be excessive if you over-fertilize.
Without photos its hard to advise on exactly where to make a height reduction pruning cut, but in general you should look for a lateral branch off the parent stem, and cut just above the point of juncture. If no laterals, you can cut mid-stem, but it will be an ugly stub for awhile until new growth appears. The other option is to remove the entire tallest stem and allow the shorter ones to remain.
Or stake the stems for artificial support.

If you have not fertilized, then I would suggest that this is a nitrogen deficiency. However, this could also be a pest related issue. Have you noticed and webbing, or strange substances on your plant?

This article will refresh you on the care of the plant: https://www.gardeningknowhow.com/houseplants/rubber-tree/how-to-care-for-a-rubber-tree-plant.htm

These are very easy and forgiving to work with. Depending on if you want them to remain smaller, or grow larger you will either cut the bottom 1/3 of the root ball before transplanting, or leave them for a larger plant. They will fill out the size container that you put them in. They will stay in a very small container for a very long time, though.

I have two articles that will help you:

https://www.gardeningknowhow.com/houseplants/rubber-tree/repotting-a-rubber-tree-plant.htm

https://www.gardeningknowhow.com/houseplants/rubber-tree/propagation-rubber-tree-plant.htm

The true rubber plant or rubber fig is Ficus elastica (big leaves). Ficus benjamina is "weeping Chinese banyan" (smaller leaves).
With the leaf drop that you describe, I suspect that your plant is Ficus benjamina, because this is a common phenomenon as a response to physiological stress. It could be due to drought stress or other factor.

https://www.plantopedia.com/ficus-benjamina/

I actually do not recommend doing this. Although they will achieve a more full look, they will also be crowded. It would be best to top the largest one each year until you get the look you want. This will lead to a more overall healthy plant. Your others can be maintained in separate pots in the same fashion. Be careful or you will end up like me, and have a forest of things that you don't have room for! I have a bad habit myself of making too many copies of plants!