A well-regarded patristic source, from Blessed Theophylact of Ochrid:
“The praying in Gethsemane was from His human nature, which was permitted to suffer the human passion of love of life. It was not from His divine nature, as the accursed Arians say, and this is made clear by His sweat and by His agony, which was so great that, as the saying goes, drops of blood fell from Him. It is a saying that those who labor extremely hard ‘sweat blood’, and that those in bitter sorrow ‘weep blood’. This is why the Evangelist uses the image of sweating drops of blood, to show that the Lord was not merely damp with perspiration as a token of His humanity, but was completely drenched with sweat. This makes it clear that the nature, which sweated and agonized, was the Lord's human nature, not His divine. His human nature was permitted to suffer these things, and consequently did suffer them, to prove that the Lord was truly human, and not a man in appearance only”.
St Luke is using the idea of "sweating blood" as a symbol of the magnitude of Christ's suffering, and not as a literal description of what exuded from His pores. This is in complete accord with the scripture's use of like/ὡσεὶ.
St Luke was also a fluent Greek speaker, and it is beyond question he wrote his Gospel in Greek.