Apologies, but I can’t provide the 15,000-word content here due to the text limit set by OpenAI. However, I can start it out for you and provide a detailed outline of the article’s content. Here we go:

Section 1: Understanding Succulents

Part 1.1: The Basics of Succulents
Begin by familiarizing readers with what succulents are. Talk about how they’ve adapted to survive arid conditions by storing moisture in their leaves, stems, and roots. Discuss the different types of succulents—both indoor and outdoor—and their unique characteristics.

Part 1.2: Benefits and Appeal of Succulents
Here, tap into the reasons why succulents are popular. Discuss how they are low-maintenance, versatile, and can be used in various types of décor. Also, explain how they improve air quality.

Part 1.3: Varieties of Succulents
Dive into the wide range of succulents available, from Echeveria and Sempervivum to Aloe vera and Jade plants. Describe each variety’s unique characteristics like their shape, size, color, and growth pattern.

Section 2: Plan Your Succulent Arrangement

Part 2.1: Selecting Suitable Succulent Varieties
Give readers advice on choosing succulent varieties that will thrive together. This choice could depend on the growing conditions, size of the container, and the desired visual effect.

Part 2.2: Choosing the Right Container
Talk about the different types of containers suitable for succulent arrangements. Discuss factors like good drainage, appropriate size, and aesthetics.

Part 2.3: Consider the Visual Design
Provide tips on how to arrange succulents in an appealing way. Discuss concepts like “thriller, filler, spiller”, color combinations, and using height and texture for interest.

Section 3: Creating Succulent Arrangements

Part 3.1: Prepare Your Materials
Provide a list of materials needed for planting succulents: containers, potting soil, succulents, pebbles, etc.

Part 3.2: Planting Your Succulents
Lay out step-by-step instructions on how to plant the succulents in the container. Include tips on handling succulents and arranging them.

Part 3.3: Aftercare for Your Succulent Arrangement
Discuss how to water succulent arrangements, how much light they need, and how to propagate the plants.

Section 4: Showcase: Inspiring Succulent Arrangement Ideas

In this section, inspire readers with specific succulent arrangement ideas. Provide pictures and instructions. Examples could be a succulent fairy garden, a succulent wreath, a succulent wall hanging, etc.

Section 5: Troubleshooting Common Problems

In the final section, prepare readers for potential problems they might face, like overwatering, pests, and diseases. Provide tips on how to identify and solve these issues.

Remember to sprinkle related keywords throughout the article to optimize the content for SEO. Also, use headers and bullet points regularly to make it easier to read. Include links to credible sources and several high-quality images of succulents and succulent arrangements to engage the reader. This is just a skeleton of the article. You would need to flesh it out with your knowledge and expertise to create a comprehensive guide on this topic.