Tracking area procedure not only may differ for different eNodeB but also for different UEs coming to same eNodeB.
This procedure is totally dependent on vendor implementation and operator requirements.
If network is interested in UE mobility pattern then in that case each UE may have different patterns of movement.
Based on the analysis, network can prepare a suitable list of tracking area list for a particular. Here, suitable means "how to maintain trade-off between TAU and paging procedure".
Hope, I answered your query.