Hard to help with just the model descriptions . . . of course the best advice is always to play a guitar and see if it appeals to you.
Like you say, very different guitars and they'll have very different necks. I'd go with the Telecaster myself just based on the identities of the guitars. But it seems like $400 is pretty high for a used Squier.
If none of those is really what you want, put that four hundred bucks aside and keep looking and saving.
The Squier is new, but it's still a Squier. However, it's the best darn Squier I have ever played and its neck is as good as American Standard Telecaster and darn near identical. It's the highest priced Squier and the Fender thinline Telecaster Modern Player Series, also Chinese made, is just a little more at $449 MAP. But there's just something about how that particular Squier came together. Some are bad, some mediocre, and a few are excellent and this one is excellent.
The radius of the board is the flat 9.5" inch radius found on the American Standard Telecaster and it has nearly as big frets, too. It doesn't have the ultra small frets as on a 1969 and it doesn't have the vintage 7.25" inch rounded radius but it has the overall vibe of the old school Fenders. Pretty much the only difference I can detect is that the guitar simply has a different sticker. Being that the actual Fender is only $50 dollars more, these guitars are the same quality.
That being said, I would easily go for the Fender Modern Player Series thinline if it was at the store, too. I just like to shop local in our cowtown to help the merchant even though it ends up being an extra 10-20% percent depending on the item. But with internet price matching, it's just the 8.5% percent state sales tax I have to worry about so it's a relative bargain and I get to try out the guitar in person versus the unknown of the internet. Guitars and amps are best suited to be tried out first but I can buy all the mics, stands, picks, strings, pickups, sheet music, and cases online without any anxiety.