If you are worried about getting browsed too much right away, tree tubes work fine for a few years. Better than not having any protection. Longer term will probably have to cage to get them to start spreading out. I have about 1/2 doz dogwoods that grew quickly with the tube greenhouse effect but now the tubes are pretty choked with multi-stems and nothing gets established outside the tube. I have to pull the tubes and start putting cages up to give them a little more critical mass before the onslaught of browsing that is likely to occur when I pull everything. I had tubes on hand and no fencing at the time so why not. If I had to buy either one to start with I would go with a cage from the start. Did just that with a couple of serviceberry among other shrubs planted last year but no quick growth like a tube gives. Hope to see some growth spurts the 2nd and years ahead.