the code below creates this diagram. I would like to to make all 3 subgraphs 5 nodes tall. so that, for example data_source_1, process_1 and product_1 are all horizontally aligned properly (same with process_5 and product_4). That would make the diagram better readable. is there a way of doing that? (I am using R to make the plot, but the issue is with the graphviz syntax).

library(DiagrammeR)

my_graph <- grViz(paste0("
  digraph {

  graph[splines = ortho,
  ordering = 'in',
  rankdir='LR',
  concentrate=true,
  labeljust= 'c',
  layout = dot,
  overlap =true,
  outputorder = nodesfirst]
  node [shape = rectangle, style = filled, fillcolor = 'blanchedalmond']
  edge[color = black, arrowhead=vee, minlen = 1]
  
  # draw lines 
  
  # from survey data to inpu
    data_source_1 -> process_1
    data_source_2 -> process_2
    data_source_3 -> process_2
    data_source_3 -> process_2
    data_source_4 -> process_2
    data_source_5 -> process_3
    data_source_6 -> process_4
    data_source_6 -> process_5

  # from input to cleaning
    process_1 -> product_1
    process_2 -> product_2
    process_3 -> product_3
    process_4 -> product_3
    process_5 -> product_4
    
  
# add clusters    
subgraph cluster_1 {
        node [style=filled]
        'data_source_1' 'data_source_2' 'data_source_3' 'data_source_4' 'data_source_5' 'data_source_6' 
        color='red';
        label = 'Data';
        style=filled;

}
    
    subgraph cluster_2 {
        node [style=filled]
        'process_1' 'process_2' 'process_3' 'process_4' 'process_5'
        color='lightblue';
        label = 'process';
        style=filled;

    }
        subgraph cluster_3 {
        node [style=filled]
        'product_1' 'product_2' 'product_3' 'product_4'
        color='yellow';
        label = 'process';
        style=filled;

    }
}"))


my_graph