When King Philip II of Spain (Philip I of Portugal) placed a trade embargo on Dutch trade with his realm, this cutoff the Dutch supplies of salt from Portugal. The Dutch relied on Portuguese salt to preserve herring, and as a result they sought out the salt of present day Venezuela. Eventually they built small settlements in the region, however as late as 1700 there were fewer than 500 Europeans in the territory, around 1/3rd of whom were Jews who had left the Dutch in Brazil.
As mentioned earlier, one of the differences between Portugal and the Netherlands was the degree to which the Portuguese settled their colonies. Portugal was much poorer than the Netherlands, and the colonies were long viewed by the crown as a place to dump poor people and prisoners to relieve tensions at home, meanwhile securing Portugal's rule overseas. This was not necessarily a profitable venture at first, but it was seen as a long-term investment. The Dutch WIC (and VOC) were for-profit concerns, largely responsible to their shareholders and therefore colonisation was a very low priority. In addition, the Netherlands enjoyed the highest standard of living at the time and tended to attract immigrants rather than repel them.
For instance the a mere 1,253 European immigrants were recorded as having arrived in the New Netherlands between 1630 and 1664. By the time the area was annexed by the British, the total population had grown to 9,000, but this included around 500 slaves. Keep in mind that this included the population of annexed New Sweden (500) and around 2,000 English living in Dutch Long Island. In South Africa too there were only 2,044 immigrants settled between 1652-1806. In both colonies around half of the settlers were Germans, Scandinavians and French Huguenots.
In contrast to the Dutch, thousands of Portuguese left their country to the colonial empire, sometimes in the most unlikely of places. The Portuguese settled 1,200 Azoreans at the mouth of the Zambezi River in present-day Mozambique hoping to establish an agricultural colony at Cuama, though the majority perished within two years. In Brazil thousands of settlers began arriving in the mid-16th century to Northeastern Brazil, and though their natural population growth actually diminished by -1% per year due to tropical diseases, the white population of Brazil numbered around 74,000 by 1660. By the time the Dutch took over Pernambuco and Rio Grande do Norte, some 200,000 Portuguese had immigrated to Brazil.
The Dutch wanted Brazil for its sugar, as it was the world's largest sugar producer at the time. The Spanish crown had placed an embargo on the Netherlands after the end of the truce in 1621, and the West Indies sugar economy had not yet developed to any great extent. The WIC attacked Salvador, but failed to capture it as it was the hub of Portuguese Brazil, however in 1635 they did manage to defeat the Portuguese at Pernambuco. Keep in mind that by this time the Tupi Indians had largely been converted to Catholicism by the Jesuits and some 2,000 accompanied the retreating Portuguese. The also converted Portiguar Indians began a guerilla campaign against the Dutch, largely due to the Jesuit influence. In 1638 the Dutch once again attempted to conquer Salvador, but failed. However, in the north they did capture São Luis in Maranhão in November 1641. This area was sparsely populated though with fewer than 2,000 Portuguese.
Trouble began in 1640 when the Portuguese crown was restored and in 1642 a revolt against the Dutch began in earnest. The WIC also began enslaving Indians to work on the salt pans, further hurting their cause. In July 1642, the Portuguese in Salvador signed a truce with the WIC officials, leading to the withdrawal of most of the WIC troops from Brazil. In October 1643 the siege of São Luis began and it was abandoned by the WIC in January 1644. This emboldened the Portuguese and in by 1645 the Dutch control was reduced to the coast of Paraiba. With the Anglo-Dutch War, the Portuguese Crown began to openly support the rebels as a way to reaffirm their alliance with the English. Despite this the Dutch blockaded the Portuguese coast so there was little support that Portugal could offer. However, the Portuguese in Brazil managed to expel the Dutch in 1654, and this was finally recognised in
1661.
In 1645, New Holland had a population of 12,543, of these 4,083 were Africans, around 3,050 were WIC military and naval personnel. Also there were around 1,000 Jews, however their population fell to 600 by 1654, and most departed with the Dutch. By contrast there were some 60,000 Portuguese in the rest of Brazil.
If the WIC had managed to keep its portion of Brazil (Ceara, Rio Grande do Norte, Pernambuco), I imagine that the Portuguese would have focussed on expanding Brazi southwards sooner. There were some 50,000 Portuguese settlers sent to Brazil in the immediate aftermath of 1660, and the Portuguese were around half of the population of Buenos Aires at the time (mostly smugglers), so you may get a situation where more move southwards, encroaching further on the most neglected of the Spanish domains, the Rio de la Plata.