You really should check out some of the "Stick Grappling" videos on Youtube. There are plenty. Also, look specifically for anything you can get by the "Dog Brothers".
Most of the stick grappling videos you'll see are going to be by people who have combined Filipino escrima / kali with Brazilian Jiujitsu. This is okay, but keep in mind that most of what you'll see is a lot of theory, because these people often don't do more than drills with it. Ie, they're not trying to see how it works at full speed in sparring. So you'll get a lot of theory, some of which looks good, some looks questionable, but mostly it's untested.
Whereas, the Dog Brothers have been doing stick grappling for decades now, but they do it much more realistically. They are a bit extreme, though. Their motto is "Higher consciousness through harder contact." When they do their version of sparring, they tend to wear Lacrosse style mitts, arm pads, leg pads, fencing / kendo helmets, etc. They go as hard and as fast as they can, swinging sticks at each other, doing kicks, punches, clinches, take-downs, and ground fighting. All of which is with and without sticks. They have no rules except that at the end of the day, they are all friends and hopefully won't have any injuries (but they often do get injured, sometimes badly). Yes, this type of training is not for most sane people!
But that doesn't mean you can't look at Dog Brothers' results and derive useful information about what works and what doesn't. You can! And you should. See what they say works. Learn their drills. Get partners that want to combine stick fighting with grappling, and do it on your own at a local park or something. Just be careful. You don't have to go to quite the same extreme they go to. And make sure you each know where your limits are and what you're comfortable doing.
The Dog Brothers do sell videos. But you can get a lot for free just looking at Youtube. Then buy the videos if you're still interested. Their web page is at: