For me it's more practical to hire a Wedding coordinator, at least a day coordinator that would take care of everything, from the church to the reception. Believe me, you don't want to assign a number of your relatives to take care of how the program flow of your wedding reception would go, how and when to distribute the wedding give aways/souvenirs, etc. Remember that your relatives are, after all, also your guests.
I have witnessed a wedding where there was no wedding coordinator. The Maid of Honor was assigned to retrieve the Unity candle at the altar, right after the Bride and Groom have finished being photographed inside the church.
Since, the Unity candle was still lit, the Maid of Honor who was also assigned to retrieve it from the altar table has to pour the melted candle wax, which has almost overflowed around the candle wick. Unfortunately, the candle wax fell on her gown and what a mess that was. A maid of horror she became.
For my personal experience, hiring a wedding coordinator is for your convenience and for all the guests, including your relatives to also just sit and enjoy the festive mood of your wedding and let the day coordinators worry about everything else.
The only downside of hiring a wedding coordinator is of course, you have to pay them.
Hiring a full wedding coordinator is another matter. Beside's being expensive, a full wedding coordinator will refer you to the most expensive suppliers who are also her tie-ups, a.k.a., business partners in the wedding industry. I do not recommend a full wedding coordinator.
However, there is an ongoing trend among full wedding coordinators wherein they are also a one-stop shop; meaning, they will offer you a full wedding package which will include the wedding invites, bridal car, gown, catering, give-aways, the works, all that jazz, etc.,
And because of the competition between wedding coordinators, they will try to come up with ths most competitive price package that is more marketable, reasonably priced and yet affordable.