Wrong!!! Biblehub says they are exactly the same:
Mark 10:8 https://biblehub.com/mark/10-8.htm
one: Strong’s Greek 1520: One. (including the neuter Hen); a primary numeral; one.
John 17:21 https://biblehub.com/john/17-21.htm
one: (including the neuter Hen); a primary numeral; one.
Give it up Elsie .... ‘you can dish it out .... but you can’t take it.’
Maybe you should take Christ’s advice:
Mark 7:5 5 Thou hypocrite, first cast out the beam out of thine own eye; and then shalt thou see clearly to cast out the mote out of thy brother’s eye.
That's ok I guess.
two
δύο (dyo)
Adjective - Nominative Masculine Plural
Strong's Greek 1417: Two. A primary numeral; 'two'.
will become
ἔσονται (esontai)
Verb - Future Indicative Middle - 3rd Person Plural
Strong's Greek 1510: I am, exist. The first person singular present indicative; a prolonged form of a primary and defective verb; I exist.
one <----------------------------------------------------------------------------
μίαν (mian) <----------------------------------------------------------------------------
Adjective - Accusative Feminine Singular
Strong's Greek 1520: One. (including the neuter Hen); a primary numeral; one.
flesh.’
σάρκα (sarka)
Noun - Accusative Feminine Singular
Strong's Greek 4561: Flesh, body, human nature, materiality; kindred.
So
ὥστε (hōste)
Conjunction
Strong's Greek 5620: So that, therefore, so then, so as to. From hos and te; so too, i.e. Thus therefore.
they are
εἰσὶν (eisin)
Verb - Present Indicative Active - 3rd Person Plural
Strong's Greek 1510: I am, exist. The first person singular present indicative; a prolonged form of a primary and defective verb; I exist.
no longer
οὐκέτι (ouketi)
Adverb
Strong's Greek 3765: No longer, no more. Also ouk eti from ou and eti; not yet, no longer.
two,
δύο (dyo)
Adjective - Nominative Masculine Plural
Strong's Greek 1417: Two. A primary numeral; 'two'.
but
ἀλλὰ (alla)
Conjunction
Strong's Greek 235: But, except, however. Neuter plural of allos; properly, other things, i.e. contrariwise.
one <----------------------------------------------------------------------------
μία (mia) <----------------------------------------------------------------------------
Adjective - Nominative Feminine Singular
Strong's Greek 1520: One. (including the neuter Hen); a primary numeral; one.