On the contrary,historically speaking,Portugal lead the way in overseas exploration in the 15th century. Who followed who?If I could thikn of a way to represent their importance and unique actions and history without being similar to Spain
"It is doubtful whether Castilian expansion would have gotten under way in the Atlantic without the stimulus of Portuguese competition. Castilian commitment to the conquest of the Canary Islands until the opportunity emerged to forestall the Infante Dom Henrique. Castilian trade licenses to Guinea in the 1470s were issued in the course of war with Portugal. The Castilian royal commision to Columbus, was in part the result of envy at the profitability of Portugalīs African trade; Magellan (the Portuguese navigator) was a reponse to Portuguese prominance in the trade of spice islands. The Dutch were drawn to the Indian Ocean in emulation of the Portuguese example. The methods and nature of the Atlantic trades in sugar and slaves in the 17th century were borrowed by almost the European states and business that took part in it..."
In the East, but Portugal was a global empire (Africa-Angola/Mozambique, etc), America ( Brazil),/Asia,Far East (Ceylon, Mollucas, Timor, etc); in Americas, Brazil, the fifth largest country in the world, by the Treaty of Madrid (1750) achieved its present boundaries, by minor adjustments, the equal of all ten Spanish colonies put together.But Portugal relied heavily on trading ports
Here is the difference, quoting,
"Broadly speaking, there was three types of longe range outreach available to imperial societies in the early modern period. They could follow trade winds (or all year prevailing systems) like the Spanish and Dutch; moonsonal systems, like those that inflated far-reaching ambitions in maritime Asia; or they could expand to landward, like Russia or China in Central Asia. The Portuguese did all three."
Source, "Portuguese Expansion in Global Context", pages 507/509, Felipe Fernandez Armesto, British Historian; Tufts University.
Preface to the John Hopkins Edition, The Portuguese Empire, Prof. A.J.Russel,
" ...I also wish to stress that the Portuguese not only were the first Europeans to establish (from a European perspective) the boundaries of the modern world, but, to a degree unmatched by any other European nation in the early modern period, came into contact, initiated exchanges, and maintained relationships with persons of greater diversity of racial, cultural, religious, and national backgrounds...finally,interconnecting the histories of four continents and multiple oceans over the span of four centuries"