The trees were planted much to close together and are shading their lower branches out as well as suffering from shade from other trees. They are never going to look good because they can’t fill out. Hard to do but the best looking trees would do better with less competition. I would take out the spindly ones next to the fuller one and consider replacing the other spindly trees with one that grows well in part shade. Black spruce should be planted about 20 ft apart. Any closer and they will eventually have to be thinned. The ash may eventually need to be taken down do to emerald ash borer. The colder winters have really slowed down the pest so for now fewer ash are dying. If the ash goes I assume a lot of shade will go too.  

If I take out the 2 center ones the remaining will be 20 feet apart. City just did a check of ash trees last spring and tagged a lot which were removed by city or homeowner.  None of these were tagged. The neighbors to the east are taking out their ashes 1 by 1 so that might be sooner.    If I took out all but the fuller one, what could I put in as replacement--or do I have to wait for ashes to go?

When you replace and what you plant depend on what you really want.  Loosing trees is sad but also a great opportunity to have a sun loving tree. I recommend thinking about the trees you have always wanted. If you want one that is an understory tree and tolerates partial shade it could be planted now and still will be ok when the ash are taken out. If you want a tree for full sun then I would wait.