Just look at a 20 and the 16, if there is no difference between the 2 except for... then I'd do it. If on the other hand one has bigger tubing or... then I might not.
A long time ago a local roofing company used to take 2 40' extention ladders and tie them together to reach the tops of very tall buildings. I heard that when you got to the center with a bundle the ladder was bent in so far you were climbing up tilting backwards.
Start tieing 2 16's together and that might be something else. lol
None of those stands come with enogh tie downs and you can always ad another stabilizer.