Both blocks would redraft into 21 inch finished size blocks quite easily.
If you are planning to use both blocks in the same piece - I would make a couple of sample blocks to see how if like how they line up together - or if you like the secondary pattern that will develop.
If you redraft them in the proportions shown - the points won't line up - if that's what you are planning to do.
ETA:
eparys already did what I was thinking!
Good illustration, eparys!
ETA some more:
If I was planning to use alternate blocks, I would have them both be based on the same grid. I think the design would flow better.
They are both lovely blocks - but I find them 'jarring' together.
But this is your project - - - -
Last edited by bearisgray; 05-24-2013 at 07:57 AM.