How managing the display order of layers

Question

groupLayerMarker is always under other layers so user can't see markers

1. map Collection:[]
2. I get data and create groupLayerMarker groupLayerMarker: [layerMarker, layerMarker ,...] Collection: [groupLayerMarker],
3. loading layerOsm
   Collection: [groupLayerMarker, layerOsm],
4. loading map layerWMS with property layer="" Collection: [groupLayerMarker, layerOsm], (layer="" so there is no layerWMS in collection.

5. user select checkbox with layerName_1 from layerWMS (layer="layerName_1")
   Collection: [groupLayerMarker, layerOsm, layerWms],

   addAllMarkersLayer() {
   const markersGroup = new LayerGroup({
       layers: [],
       name: 'marker',
       id: 4
   });
   this.map.addLayer(markersGroup);
   markersGroup.setZIndex(markersGroup.get('id'));
   

   }

   addLayers(mLayersComponent: QueryList < MLayersComponent > ) {
   const results = first < any > (mLayersComponent.toArray());
   forEach(results, result => {
       if (result && result.length > 0) {
           result.forEach(map => {
               map.layer$.subscribe(newLayer => {
                   if (newLayer) {
                       this.removeOldLayers(newLayer);
                       this.map.addLayer(newLayer);
                   }
               });
           });
       }
   });
   

   }

   removeOldLayers(newLayer) {
   const newLayerName = newLayer.get('name');
   const allLayers = this.map.getLayers();
   allLayers.forEach(existingLayer => {
       if (existingLayer && existingLayer.get('name') === newLayerName) {
           this.map.removeLayer(existingLayer);
       }
   });
   

   }

I tried to add zIndex to move groupLayerMarker to top Collection: [layerOsm, layerWms, groupLayerMarker].

In future i need add another layers like layerRoads order should be: Collection: [layerOsm, layerWms, layerWMTS, groupLayerRoads, groupLayerMarker]

Question: How manage layers ?