Lavrentivs wrote:I know that, but combined with the enclitic it has the circumflex of the antepænult, which is impossible.
You do not replace the circumflex with an acute. However, if there is a circumflex just before the last syllable, then you have circumflex and acute, one after the other. οὗτοι οἱ ἄνθρωποι στρατιῶταί εἰσι.
These men are soldiers.πέλτη τῷ πελταστῇ ἐστιν ἀγαθή.
The targeteer has a good shield.
In the second example, the accent of ἐστί(ν) is simply lost because it follows a circumflex. Do you see the difference?