You can try experimenting with append and base searches. This is essentially using one search to power the entire dashboard. There are some limitations like no more than 10,000 results can be post-processed and you shouldn't run anything that returns raw data. The base searches link also provides some usage examples and techniques for getting the job done.
Append will chain your searches together and will execute the searches sequentially but will return a single data set. You should account for this in your post-processing by limiting fields that are returned from the base search and used in the post process searches.
I've done something similar in a service level dashboard I developed for my company's NOC which about 25 dashboard "icons" that are powered by only 3 base searches.