The tree service took down as far as they could??? They did the easy stuff and left the stump for the homeowner? Even with a small saw they could have taken it to within inches of the ground if they knew how to use a saw hammer and wedges. My thoughts are it was getting too big to handle easily and so they left it. When faced with a large tree and all you have is a small saw (reads short bar) you can do horizontal cuts a foot apart all the way around the tree about a foot apart. Tip burried, walk the saw around the tree, raise up a foot or so and do it again. Then tip in cut a vertical, move over 6" and cut a second vertical from the top of the upper horizontal to the bottom horizontal and hit it with your hammer to knock the wood out. Knock it out all the way around the tree. This gives you a space to get a second bite at the stump and from here you can get the tree (stump) over. If you need do a third horizontal, do it. Usually, you don't need to do a third horizontal. Reach in and do your notch and then back cut and over it goes. I did do 4' diameter cherry tree with a Husky 335 Cali and 14" bar this way to test the saw's preformance. Hey, the guy that modded the saw said it would preform and I was determined to find out or kill the saw trying. Needless to say, that was a brutal test for a trimming saw but it is was the first two tanks of fuel through the saw and it is a winner. If you can't plunge cut with your saws you need a better saw/chain setup. IMHO The tree service quit early because no one wanted to put out the effort to get the stump down all the way and have to load out the big stuff at the end of the day. Maybe they don't push their saws hard enough. Maybe they cut and run from the hard stuff. You don't leave a stump that big unless the homeownner asks you to.