Would you like the long or the short answer?
The short answer is of course not. It's YOUR wedding, you don't HAVE to do anything.
However, there are definite advantages to matching your groomsmen to the bridal party and there are so many options and ways to do it. Weddings have become so creative in the past ten years that you can really find some incredibly niched ideas to make your big day unique. A big part of that has been the rise in social media, but that's a whole other topic entirely, which you can, incidentally, read about here - The Pinterest Age of Weddings.
Matching your bridesmaids to your groomsmen is a great way to run an aesthetic and theme through your big day. It has a sense of unison for the wedding party.
Colour Matching Accessories
There's a whole array of items you can colour match these days. The most popular is probably colour matching the wedding ties. They're by far one of the most standout items of clothing after the dresses and suits and they're so easy to match to the theme of your weddings.
Different coloured bridesmaids dresses? That's okay! You can just match the groomsmen's neck wear to each of them!
Are your flowers pulling through most of the colours in your wedding scheme? Well guess what? You can match to those too.
There is literally nothing you can't match to these days! People have colour matched the groomsmen to the bridesmaids and then to cake...
...pets (he is a dapper doggy though)...
... and even hair!
So whilst you don't HAVE to match the groomsmen to the bridesmaids it can have some incredible advantages. Colour can really accentuate the personality and theme of your wedding and the options I've listed here are only just the tip of the iceberg! Just think you can add a splash of colour to anything - sashes, cummerbunds, table runners or...
(my personal favourite photo) socks!
Coordinate. Not Match
There are other options if you didn't want something so specific as matching. You could use complimentary colours to accentuates your schemes.
Or even try an unusual suit colour.
So in conclusion, no, the groomsmen don't have to MATCH, as there are lots of different ways to tie in colour themes but you can see from this article just what a difference colour matching can make. It's a simple touch that adds so much unity and personality to your big day.
If you would like to see a multitude of weddings with varying degrees of groomsmen matching to the bridesmaids, check out this compilation video of 2018 weddings.