No. It's been a while, but I believe if you use multiple TXTs, resolvers can reorder them as they see fit. For example,

label IN TXT "foo " IN TXT "bar " IN TXT "baz"

You can have any number of TXT RRs with a label, allowing up to 65,280 bytes. However, resolvers can reorder those 3 TXT RRs.

If you put the text strings in quotes in a single TXT RR, e.g.:

label IN TXT "foo " "bar " "baz"

You'll get "foo bar baz" and each of the strings can be up to 255 bytes. I think (but I'm too lazy to verify) that the maximum length of a concatenated string is implementation dependent.