I think we should keep it simple at the beginning, maybe regular merge would be enough. 
Something like:
```php
$fullConfiguration = array(); 
foreach ($this->kernel->getBundles() as $bundle) {
    if ($this->hasDataGridConfiguration($bundle->getPath(), $dataGrid->getName())) {
        $configuration = $this->getDataGridConfiguration($bundle->getPath(), $dataGrid->getName());
        if (is_array($configuration)) {
            $fullConfiguration = array_merge($configuration, $fullConfiguration);
        }
    }
}
```