Ministers have very full appointment books. A wedding usually means many hours of preparation, not to mention the time for the rehearsal and the ceremony. That's why it is wise to contact the pastor before setting the date for a wedding.
There is a lot of flexibility in a Lutheran wedding ceremony. Most Lutheran pastors will work with you to make your wedding fit your personal choices if those choices are appropriate to Lutheran theology and practice. However, some busy pastors insist on limiting your choices because they know from experience what will and will not work in their setting and in their timetable.
A word of advice from a pastor who has married many couples. Over the years I've found that the simple ceremonies are usually the most impressive and memorable for all the right reasons.