Presumably you refer to the iPad's markup and drawing toolbar - as used by native Apple Apps.
While you can select between different tool properties, you cannot alter the sequence of tools or otherwise customise the appearance of the toolbar. Some third-party Apps may offer a more comprehensive range of controls or options.
Apple does invite submission of comments and feature requests via its Product Feedback portal. If you would like to see additional controls or functionality released in a future version or iPadOS, this would be the most appropriate channel through which to make a request:
Feedback - iPad - Apple