Vega spec Bee swarm with Unknowns

spec.json

{
  "$schema": "https://vega.github.io/schema/vega/v5.json",
  "description": "A beeswarm chart example that uses a force-directed layout to group items by category.",
  "width": 950,
  "height": 400,
  "padding": {"left": 5, "right": 5, "top": 0, "bottom": 30},
  "background": "#ffefd9",
  "autosize": "none",
  "config": {"axis": {"labelFontSize": 15, "labelFont": "GothamNarrow"}},
  "signals": [
    {"name": "cx", "update": "width / 2"},
    {"name": "cy", "update": "height / 2"}
  ],
  "data": [
    {
      "name": "turnover",
      "url": "https://wikirate.org/Home_Office+Turnover_range+Answer.json?view=answer_list&limit=0"
    },
    {
      "name": "revenue",
      "url": "https://wikirate.org/Australian_Border_Force+Revenue_range+Answer.json?view=answer_list&limit=0"
    },
    {
      "name": "garment_companies",
      "url": "../assets/cached/MSA_Garment.json",
      "transform": [{"type": "formula", "expr": "'Garment'", "as": "sector"}]
    },
    {
      "name": "financial_companies",
      "url": "../assets/cached/MSA_Financial.json",
      "transform": [{"type": "formula", "expr": "'Financial'", "as": "sector"}]
    },
    {
      "name": "hospitality_companies",
      "url": "../assets/cached/MSA_Hospitality.json",
      "transform": [
        {"type": "formula", "expr": "'Hospitality'", "as": "sector"}
      ]
    },
    {
      "name": "companies",
      "source": [
        "garment_companies",
        "financial_companies",
        "hospitality_companies"
      ]
    },
    {
      "name": "assessed_statements",
      "url": "https://wikirate.org/~12621772+Answer.json?view=answer_list&limit=0&filter[year]=latest&filter[value]=Yes",
      "transform": [
        {
          "type": "lookup",
          "from": "turnover",
          "key": "company",
          "fields": ["company"],
          "values": ["value"],
          "as": ["turnover"]
        },
        {
          "type": "lookup",
          "from": "revenue",
          "key": "company",
          "fields": ["company"],
          "values": ["value"],
          "as": ["revenue"]
        },
        {
          "type": "lookup",
          "from": "companies",
          "key": "id",
          "fields": ["company"],
          "values": ["sector"],
          "as": ["sector"]
        },
        {
          "type": "formula",
          "as": "size",
          "expr": "if(datum.turnover == 'Under £36 million'  || datum.turnover == '£36 million to £60 million' || datum.turnover == '£60 million to £100 million' || datum.revenue == 'AU$ 0-99M' || datum.revenue == 'AU$ 100-150M' || datum.revenue == 'AU$ 150-200M' || datum.revenue == 'AU$ 200-250M', 'Small','Unknown')"
        },
        {
          "type": "formula",
          "as": "size",
          "expr": "if(datum.turnover == '£100 million to £500 million' || datum.revenue == 'AU$ 250-300M' == datum.revenue == 'AU$ 300-350M' || datum.revenue == 'AU$ 350-400M' || datum.revenue == 'AU$ 400-450M' || datum.revenue == 'AU$ 450-500M' || datum.revenue == 'AU$ 500-600M' || datum.revenue == 'AU$ 600-700M' || datum.revenue == 'AU$ 700-800M', 'Medium',datum.size)"
        },
        {
          "type": "formula",
          "as": "size",
          "expr": "if(datum.turnover == 'Over £500 million' || datum.revenue == 'AU$ 800-900M' || datum.revenue == 'AU$ 900M-1BN' || datum.revenue == 'AU$ 1BN+', 'Large',datum.size)"
        },
        {
          "type": "formula",
          "as": "sector",
          "expr": "datum.sector == null ? 'Other' : datum.sector"
        }
      ]
    },
    {
      "name": "statements",
      "source": ["assessed_statements"],
      "transform": [
        {
          "type": "lookup",
          "from": "companies",
          "key": "id",
          "fields": ["company"],
          "values": ["name", "headquarters"],
          "as": ["name", "headquarters"]
        },
        {
          "type": "formula",
          "expr": "datum.revenue == null ? 'Unknown' : datum.revenue",
          "as": "revenue"
        },
        {
          "type": "formula",
          "expr": "datum.turnover == null ? 'Unknown' : datum.turnover",
          "as": "turnover"
        }
      ]
    }
  ],
  "scales": [
    {
      "name": "xscale",
      "type": "band",
      "domain": {
        "data": "statements",
        "field": "size",
        "sort": {"order": "descending"}
      },
      "range": "width"
    },
    {
      "name": "color",
      "type": "ordinal",
      "domain": {"data": "statements", "field": "sector"},
      "range": ["#ffdc00", "#DDDDE3", "#ff9300", "#000028"]
    }
  ],
  "axes": [
    {
      "orient": "bottom",
      "scale": "xscale",
      "domainWidth": {"value": 0},
      "ticks": false,
      "encode": {
        "labels": {
          "interactive": true,
          "update": {
            "tooltip": {
              "signal": "datum.label == 'Small'? {'turnover':'less than £100M','revenue': 'less than AU$ 250'} : (datum.label == 'Medium' ?{'turnover':'between £100M and £500M', 'revenue':'between AU$ 250M and AU$ 800M'}: {'turnover':'over £500M','revenue':'over than AU$ 800M'})"
            }
          }
        }
      }
    }
  ],
  "marks": [
    {
      "name": "nodes",
      "type": "symbol",
      "from": {"data": "statements"},
      "encode": {
        "enter": {
          "fill": {"scale": "color", "field": "sector"},
          "xfocus": {"scale": "xscale", "field": "size", "band": 0.5},
          "yfocus": {"signal": "cy"},
          "tooltip": {
            "signal": "{'Company': datum.name,'Sector': datum.sector, 'turnover (range)' : datum.turnover, 'revenue':datum.revenue}"
          }
        },
        "update": {
          "size": {"signal": "pow(2 * 5, 2)"},
          "stroke": {"value": "white"},
          "strokeWidth": {"value": 1},
          "zindex": {"value": 0}
        },
        "hover": {
          "stroke": {"value": "black"},
          "strokeWidth": {"value": 3},
          "zindex": {"value": 1}
        }
      },
      "transform": [
        {
          "type": "force",
          "iterations": 200,
          "static": false,
          "forces": [
            {"force": "collide", "iterations": 1, "radius": 5},
            {"force": "x", "x": "xfocus", "strength": 0.2},
            {"force": "y", "y": "yfocus", "strength": 0.1}
          ]
        }
      ]
    }
  ]
}