The problem with your question is that you're including a premise you haven't proven true. Namely that a lesbian will dress & act like a man to attract another lesbian. Actually, that premise is rather flawed. If a lesbian were attracted to men she wouldn't be a lesbian.Still asking;
WHY does a lesbian dress and act like a man to attract another lesbian?
How does that make sense according to evolution?
Isn't there anyone with a validated explanation?
If you want to discuss the way people dress that might be a better starting point for you.
Personally, I prefer to wear denim and tee shirts or work shirts (depending upon weather) as these suit my working conditions and comfort. I dress the same going out to eat in your average restaurant. If I'm going out to a nice place I'll wear a nice pair of jeans instead of the faded ones I wear while working. I'll wear a more casual styled shirt on those occasions. Rarely will I put on a suit. This isn't in order to attract anyone. It is just the way I am. I don't do all the smell good stuff either, that is no substitute for good ol' soap and water.
If you want to further the discussion about sexaul attraction, if my appearance is appealing to a woman, then odds are good she's going to be in the ballpark when it comes to being my type. It has been said that you can tell a lot about a person by the way they dress. Sooo, I'm not apt to draw the attention of some prissy uptight woman who is afraid to get a bit wet out riding on a bike. In short I wear what I feel comfortable in and if that attracts someone, so be it. If it doesn't that ain't no big thang either. This is the way I presented myself well before I met and married my wife and it appears that I'm not going to change anytime soon.
Moving right along to address your question directly, sort of. Are you suggesting that this is the way all lesbians dress? If so I think you're basing your question on a fairly narrow stereotype that doesn't necessarily apply to very many. Yes, I've seen some fairly butch lesbians. Oddly enough I see them as couples. OTOH, there are the two women living on the property next to mine. I'd hardly call their appearances butch at all. They were clothing that flatters their figures and they both wear make up and appear to be quite feminine IMHO. By the same token I know a fair number of straight men that primp and preen & go for the latest styles and load themselves up with cologne. They usually end up with women I find to be a bit tedious.
Hey ho, to each his (or her) own. People wear what they feel comfortable in. You probably won't find a corporate executive hanging out in bib overalls too often.