From the moral point of view, it does not seem right. And yes, a girl with serious intentions may not like the fact that you are planning to meet more than one potential match.
On the flip side, girls should understand that you are venturing a lot.
During the meeting, just be yourself and act the same way you would normally act meeting a girl in your own country.
A couple of red flags to watch out for (should be pretty logical, but you don't see things the same way you do when you are infatuated): Well, you got the point.
As a single man: If you are in Ukraine and would like to meet someone for a serious relationship, here is what I suggest that you do: Here everything is simple as it does not really matter which city you visit. Think of activities you would enjoy doing while in our country: visiting historical sites, getting some tan on the seaside etc.
Below is a couple of reasons: If you liked one of the girls and believe that the attraction is mutual, make sure that you obtain her number (otherwise you will end up talking to her through the agency and they will continue ripping you off for their services).
Based on what you want, settle upon a city you want to go to.